Pim Schellart [X] suggests I might want to weigh in here, so: my preference is for explicit deletion rather than a mixin. But it's sufficiently slight that I wouldn't have bothered mentioning it if Pim hadn't asked, so I'm certainly not going to complain if you jump in the other direction.

Ok, so given nobody (including me) has a strong preference, and assuming John Parejko doesn't object, I'm going with the explicit delete option. It seems to offer the least amount of possible limitations in the future.

Given that my only objection was overruled (not without good reason!), this is ok to merge.

Merged after final CI run. Thank you for the review!

SPs contained in parent issue.