couldn't find pointer issues, but my instinct tells me it's a bit risky ^^ also, did write some fuzz tests and ran for sometime, nothing found, but since we have a hint that does all the work, it just says the hint seems to be correct, not that everything is sound and one can't find a bad :)

lgtm 👍

Yes, it is not perfect, but imo works well enough. I have some ideas on how to make it more robust. Namely we can keep some DB of "element pointer -> hash of limbs" and if we see during some non-native operation that there is a conflict then we can panic.

The problem with using values was that then I cannot re-use the element-as-polynomial evaluation value when same element is used in multiple muls. And this really impacted some non-native code. I could possibly try having some additional DB "hash of limbs -> stored evaluation", but dunno if this would be any better than the current approach + integrity check in prev paragraph.