Thoughts on improving B902?

I think B902 is great for detecting errors like this:

@classmethod
def foo(self):
    ...

However, I also find myself # noqa:ing it a bit too frequently. Here are some instances where I think it could be safely relaxed for everyone:

• Allow _cls instead of cls (ditto for metacls). Rationale: this can be required when a method needs to take, or transparently pass through, a keyword argument with one of these names.
• The first argument to __new__ of classes that subclass type should probably be called metacls, not cls. And similarly — regular instance methods on metaclasses should take cls, and any classmethods should take metacls.
• Consider allowing subcls / submetacls (depending on inheritance) for __init_subclass__, since that is actually significantly clearer.

What do you think?

Start at the B902 rule entry point and review how it currently handles classmethod, new, and init_subclass. Compare the proposed _cls, metacls, subcls, and submetacls cases with the existing behavior; done requires an agreed scope and verified rule changes.