As noted on the PR, bikeshedding season on the name is now open - @takluyver preferred something specifically relating to the backend, like
backend-path, and I’m inclined to agree with him. But if we end up going for
python-path[s] then I agree with your reasoning that
path is better.
If there’s a significant debate over names for the key, what I’ll probably do is set up a vote here, and go with a simple majority preference. I don’t want to have naming trigger a whole other round of debates on semantics.
Regarding the check, we can debate actually adding it in the relevant frontend trackers (
pep517). Unless you’re objecting to stating that we don’t support using this feature when using a standard (not in-tree) backend, I think “frontends MAY” is weak enough to satisfy your preference for not bothering with an actual check.