In many cases when you changed getTargetList to a classmethod you changed the body to call cls.getTargetList(...) instead of <parent_class>.getTargetList(...), which I think should cause an infinite loop. If this works I am very puzzled why. In any case, I think all such changes should either be reverted or changed to super().getTargetList(...)
There is a small benefit to one task in pipe_tasks, which is an existence proof that this change is useful. On the other hand, the improvement is fairly small and the cost is rather high in the number of packages that need editing. I lean towards dropping this ticket but am happy to approve it if you fix the calls to cls.getTargetList.