StanLemon

That's in part because we are heavily restricted by real world physics. Scadrial has numerous powers that are exceptionally useful for making space travel much more viable. So I could see Scadrial being space age in just one or two hundred years, especially considering they rebounded from near societal collapse and advanced to turn of the 20th century development in only a handful of centuries.

Considering that there was a network of interplanetary trade as early as TFE, it's quite reasonable that at least an early form of them existed during that time

Reading through this chain I have a few comments. First, Steelpushing and Ironpulling make monumentally more sense if you think of them as applying an identical force on the metal and Allomancer. It's only because of Newton's third law does the lighter object move, not some intrinsic aspect of heavier vs lighter objects. A good example of this is when not-Wax Duralumin fueled Pushes off a car and the car is flattened from the force of the Steelpush while he's launched into the air. If it was just his weight vs the car he could never flatten it like that , but it makes a lot more sense if the care suddenly had an incredible force applied to it and nowhere to go. I think there is plenty more we don't know about how Pushing/Pulling work but it does seem the more power put into it the less counterbalance of weight matters. Secondly, we see near Vin Ascension levels when Wax uses the Bands. He Pushes a boulder off of him by the trace metals in it. And then proceeds to use a Steelpush that smashed through a stone wall

The Sunlit Man seems to have given given us an explanation why Breath from children is considered better than from older people. The Investiture thresholds are similar in concept to Heightenings. According to Sigzil as long as he retains certain levels he gains abilities, and while those abilities do use Investiture, it's only a tiny amount. Applying this logic over to Breaths and Heightenings, the benefits of Breath, even just one very slowly use up the Breath. This difference between a young and old Breath is probably small enough that it doesn't make much of a difference between dozens or maybe even hundreds of Breaths, but on the scale of 10s of thousands it like Susebron, it could make enough of a difference to explain why they get their Breaths from children for the Returned.

So a while back on one of the Fullborn vs Radiant threads there was a lot of talk about mass and density and how F-Iron doesn't make sense. I threw out an equation off the cuff about how to ro rectify this m=(p x V) x I m - mass p - density V - volume I - Investiture There were a few issues with this as it was a quickly put together equation. But one of the arguments was that it implies Investiture changes mass and things like Nightblood were brought up that it isn't super heavy etc. However this book does straight up say that high levels of Investiture seemingly does alter mass. Or at least acts as additional mass on spacetime. A line from the book also caught my attention The part I found interesting, which admittedly could be reading too much into the wording, is the implication that even though it has this mass like property it doesn't affect density. This could explain some of the F-Iron weirdness in that the Investiture for Iron Feruchemy could be going toward just this property of Investiture thus explaining the mass/density contradiction partially. There are other issues but it could be a start

I trust that Brandon will make future Scadrial more nuanced. Especially because a) Sigzil's comment about Scadrian factions and b ) the final series in the Cosmere will be Mistborn series but it sure feels like he's presenting them as the "bad guys"

Except the Shroud stops existing at the end of the book. It's like saying a Returned who has used their Divine Breath is still being kept alive by that Divine Breath that doesn't exist anymore. All Cognitive Shadows we know of need something to hold their physical bodies. There Heralds need the Oathpact, Kelsier needs his Spike, the Returned need Divine Breath. Yumi doesn't have that limitation With the Shroud dissipating at the end, it's not there to hold her physical body. I agree with you that her regrowing a body isn't any different than Investiture healing, but I think it's fair to say she's not a Cognitive Shadow anymore and truly came back to life

I'm assuming she's a flesh and blood human again. All the other Cognitive Shadows we know of need some kind of "tether" to have physical bodies like Kelsier's Spike, The Oathpact, Divine Breath, etc. There's nothing like that even hinted at to be the case at the end of the book

Here is a thought, maybe it's related to how younger Breaths are better than older Breaths. It could be linked to the life force of the user

Ah, my apologies then. The last time I had read that page, the part about the newest edition retconning that hadn't been in the Coppermind.

That's exactly what I'm saying, none did. During that conversation Elend thinks to himself about the standard Spikes an Inquisitor has and is surprised that there is an extra Spike in that specific Inquisitor. And he's surprised when it's Pewter. It wasn't until the reveal that it is a Pewter Spike that they even start thinking that it's a third power from Allomancy and Feruchemy because he starts thinking about how Allomancy and Feruchemy use different metals for different effects. None of Elend's line of thinking makes any sense if any of the Inquisitors in Kredik Shaw had any Spikes other than Steel or Bronze

He couldn't have had F-Gold for one very simple reason. The only Spikes that Vin or Elend had seen from any Inquisitors before HoA were Steel and Bronze. This means Kar could not have had Feruchemy

I'm personally a fan of A-Bendalloy and F-Steel as a Twinborn combo

Considering Inquisitor's are described as aging slowly and living longer, Spikes do no cause faster aging. It's more likely that those that 'burn up' are simply overtaxing their bodies like someone who does too much labor breaks down their body. Also, though it might be an effect of Pewter Allomancy boosted by Hemalurgy, Kar the Inquisitor that Vin harmed and was fully healed by the time she next saw him only hours later could not have had Feruchemical Gold so he clearly had a higher healing rate than a normal person rather than a reduced rate

There's the character named 16 in Rhythm of War

I very much would love more A-Gold in the books. Your reference to Everything, Everywhere, All at Once is how I often have viewed how it could be used. In fact a few years ago me and my group played a MAG where we let A-Gold be rolled for that exact effect giving Traits for my character. My inspiration for that though was from Emperor's Soul and the use of Soul Stamping. An alternative life you could have lived with skills you could have developed.

Brandon has made a comment that Steel/Iron burn quickly but Allomancers generally don't notice because they aren't Pushing all the time. This implies to me that burning it for the blue lines is slow but burns faster when actually Pushing/Pulling. This would be in line with his comment about burn rate being tied to how much work the Investiture is doing. As to your second question. Weight matters, but it isn't the determining factor for strength of Pushes/Pulls exactly. Think of the blue line as a force acting equally on both the Allomancer and the metal. When a Coinshot Pushes, the force is Pushing against the Allomancer and metal identically. Per Newton's 3rd law, any action has an equal and opposite reaction. This leads to a greater amount of net force being applied to the lighter object which then moves away from the heavier object. As far as your third question goes, I personally think that it doesn't require burning any more Steel or Iron. The greater mass of the metal seems to naturally translate to thicker blue lines that can be seen at greater distances. In effect a Coinshot would be Pushing harder off of it, but that's more of a consequence of the greater net force acting on the Coinshot

Additionally he has said they are more flexible than the medallions

A sword used by a 5 ft Koloss was so heavy that Elend barely could lift it. As Koloss take larger swords as they get bigger this would imply that a sword used by a 5ft Koloss is at least the approximately the size of a claymore if not even heavier. As far as their strength goes in general, during the siege a Koloss throws a rock with enough force to hit a soldier, crush his face, and still have enough force to throw him off the wall. I've been on the top of defensive walls before and it would have to knock the soldier several feet backwards to do that. That implies a great deal of strength

So a gorilla is anywhere from 5-10x the strength of a person. Answers i found from Google varied but were around that range. From muscle mass alone I could see a 12 foot Koloss being at least on the lower end of that scale. Add in the 4 Iron Spikes extra strength it's probably safe to say that a 12 foot Koloss approaches 10x human strength even if not quite reaching it.

Oh I'm sure that they aren't, just that they are indeed stronger that their size would imply. Considering what is shown in the books, a 5 footer is probably around that strong. Though Vin never does match a Koloss strength for strength which makes it hard to judge. But considering that she uses a sword longer than she is tall, it would require a massive amount of strength. Zweihander's which are of comparable length are really really heavy swords

The strongest person in the world is still going to die by a knife. Elend took the chance because he needed to know how they were being 'controlled' and he even acknowledged that the reason he killed it is from a surprise attack. It also helps that Koloss are incredibly dumb and Elend knew that they have trouble even understanding the concept of a smaller opponent attacking a bigger one which made his surprise attack even more effective

Incidentally this WoB only talks about storing while sleeping. It's still entirely believable that a Feruchemist can unconsciously tap their metalminds, like how metals can be burned unconsciously

Oh yes, based on all incidental evidence from the books, such as that example with Elend and the Koloss, that Lerasium Mistborn could take control of Kandra when even Vin (an already stronger than average Mistborn herself) had difficulty doing so with Duralumin, and the sheer number difference of Koloss that Elend and Vin could take control of in a single Duralumin fueled Soothing. It's safe to say that a Lerasium Mistborn just flaring their metals can compete against other Mistborn using Duralumin.

One thing that can probably be confirmed is that none of the Inquisitors at Kredik Shaw had Feruchemy. Not even Kar despite his quick healing. The main proof for this? Vin and Elend hadn't come across any Spikes other than Steel and Bronze prior to HoA