> to rewrite some feature for a tiny security benefit
For what it's worth, the zero->one introduction of a new language into a big codebase always comes with a lot of build changes, downstream impact, debate, etc. It's good for that first feature to be some relatively trivial thing, so that it doesn't make the changes any bigger than they have to be, and so that it can be delayed or reverted as needed without causing extra trouble. Once everything lands, then you can add whatever bigger features you like without disrupting things.
For what it's worth, the zero->one introduction of a new language into a big codebase always comes with a lot of build changes, downstream impact, debate, etc. It's good for that first feature to be some relatively trivial thing, so that it doesn't make the changes any bigger than they have to be, and so that it can be delayed or reverted as needed without causing extra trouble. Once everything lands, then you can add whatever bigger features you like without disrupting things.
No comment on the rest of the thread...