Not quite, what's being proposed is using Endowments power (Breath) in Preservations system (Allomancy) to produce an enhanced version of Endowments power (More Breath)
That said I doubt this would work since I think Nicrosil would just convert it into generic Investiture, destroying any link to Endowment. Now if you burned an Awakened piece of metal you might be able to get more Breath out of it.
What's being discussed is imitating the properties of another Shards system (In this case Breath) not the Intent of the Investiture, this is something Brandon has explicitly said could happen, he mentioned that Preservation could produce an ability of foresight similar to Atium.
Also, it being possible doesn't necessarily mean that Odium is aware of or capable of it.
Yeah, that's what I think would happen if you burned an Awakened piece of metal. Or in the case of an Awakener who is also an Allomancer that tapping any Nicrosilmind could be used to boost your breath-count.