

You seem to have come to the same conclusion I did, in a sense, but via a different route: the first option, imo, is to alert the instance admin as to what is going on within their instance. If they are unaware, they cannot stamp it out.
After they’ve been made aware, if they either choose to actively or passively condone such behavior then defederation is called for. If they continually “slip up” and such content falls through the cracks repeatedly after they’ve been made aware, that would also be grounds for defederation.
My stance is that the first course of action should be to actively push these bad actors out of spaces that they seek to take over rather than leave those spaces to them.
Easiest PTB so far.