Docs.rs currently supports metadata of this format:

[package.metadata.docs.rs]
all-features = true

Sometimes crates have "private" features; which shouldn't be documented on docs.rs. It is possible to use doc(hidden) on these, but it would be preferable if docs were not broken for these features when they're actually desired.

It would be nice to be able to supply a denylist of features that do not get run with all-features. AIUI the code currently just passes --all-features in, so it would probably need to be tweaked to use cargo metadata to get the full feature list.