Aliroz-The-Confused

This leads to the following questionable opinion:  "weighting completed stories as 1, incomplete stories as numbers between zero and one, and assuming for no actual reason (other than that for the set "all x and y such that 0<x<1 and 0<y<1" the average for x+y is equal to 1) that the two incomplete stories together are equivalent in weight to one, measuring like an opinionated weirdo gives the '05-'09 run a weight of four and everything since a weight of one.  Thus, an opinionated weirdo's assessment of the Cosmere ought to be at least 80% based on the '05-'09 run."

(I am aware that this is not how weighted analysis works.  I majored in stats.  I am aware that you can't just remove everything from the dataset until it gives the result you want, this is intentionally silly anti-reason.)

With this in mind, I have begun constructing an unfair framing in which Elantris, the first Mistborn trilogy, and Warbreaker are the essential Cosmere and everything else is "extra stuff set in the same universe".

This actually works pretty well from a "what to recommend" standpoint.  Someone can be satisfied reading Elantris and nothing else, same for The Final Empire, same for Warbreaker, same for The Final Empire+The Well of Ascension+The Hero Of Ages.  Any combination of these can work as a complete "You can read these and be satisfied because the setups are paid off, loose ends are tied off, itches are scratched, and the ending is a happy one so you're left with a feeling of resolution rather than tension" body of work.

Everything else (of the Cosmere books I've read) is journey without destination (or, rather, journey without currently-existing-in-printed-form destination), except Tress of the Emerald Sea.

Not that the journey isn't awesome, it is.  My point is that the destinations can also be awesome and the '05-'09 run deserves kudos for the destinations it provided at the end of its journeys.