I think ultimately the argument you want to make really is the “enlightened laziness” one: there are lots of optional Pandas-y parameters in your superclass(es), and most of them you will definitely never care about, but a few of them you actually might occasionally care about. What then? Well, if your Y class is part of mission-critical interface code that lives depend on, you probably do need to work out which those are and get them nicely documented and statically checkable, but in a lot of cases it isn’t nearly worth that much effort—just make Y pass everything through, and the couple places you end up needing to pass down one of those Pandas-y arguments you just do so, and it works, and that’s fine.