I’d probably do this for a hobby project

but financial software? no way in heck!

I’ve read the thread; Rust-folk I recognize seem to accept that this was done to reduce compile time without suspecting bad-faith, but I can’t independently verify that.

There’s a post in there where sometime tries to manually compile the same binary to verify that it matches the shipped binary and they were not able to do it, but there could be a good reason for that. Reproducible builds are hard.