I'll also rename the PR title, as people tend to want to open PRs to 'fix' the changelog on intentional typos.

Thanks for the review, and great points!

I've updated the alias to an actual method, like so:

    def contains_branch_seperately(self, other_transform):
        """Permanent alias for backwards compatibility (historical typo)."""
        return self.contains_branch_separately(other_transform)

As you note, this means we no longer need additional aliases in child classes or mixins.

When I tried to remove the alias completely from transforms.pyi, the CI tests failed. But we should be able to do it pretty minimally. Instead of duplicating the type hints, I simplified that down to a single line:

contains_branch_seperately = contains_branch_separately  # Alias (historical typo)

And I removed the code from BlendedMixin in transforms.pyi.

That seems to make CI happy, and I think that's about as minimal as it can get in transforms.pyi, but of course LMK if you prefer a different solution. (One alternative could be a @no_type_check decorator in transforms.py, for instance.) I'm of course totally happy to change it up if you prefer something else.

When I tried to remove the alias completely from transforms.pyi, the CI tests failed. But we should be able to do it pretty minimally. Instead of duplicating the type hints, I simplified that down to a single line:

Ah, good point, I forgot we check for consistency. This is fine as it is.