The knightian in IB is related to limits of what hypotheses you can possibly find/write down, not—if i understand so far—about an adversary. The adversary stuff is afaict mostly to make proofs work.
I don’t think this makes a difference here? If you say “what’s the best not-blacklisted-by-any-knightian-hypothesis action”, then it doesn’t really matter if you’re thinking of your knightian hypotheses as adversaries trying to screw you over by blacklisting actions that are fine, or if you’re thinking of your knightian hypotheses as a more abstract worst-case-scenario. In both cases, for any reasonable action, there’s probly a knightian hypothesis which blacklists it.
Regardless of whether you think of it as “because adversaries” or just “because we’re cautious”, knightian uncertainty works the same way. The issue is fundamental to doing maximin over knightian hypotheses.
I don’t think this makes a difference here? If you say “what’s the best not-blacklisted-by-any-knightian-hypothesis action”, then it doesn’t really matter if you’re thinking of your knightian hypotheses as adversaries trying to screw you over by blacklisting actions that are fine, or if you’re thinking of your knightian hypotheses as a more abstract worst-case-scenario. In both cases, for any reasonable action, there’s probly a knightian hypothesis which blacklists it.
Regardless of whether you think of it as “because adversaries” or just “because we’re cautious”, knightian uncertainty works the same way. The issue is fundamental to doing maximin over knightian hypotheses.