Well, the idea behind "perfect celestial beings" kind of is to ignore physical constraints.

"I think the bottom line is that 'unbounded', instead of 'really frickin large', is a tough bar to pass and it should not carelessly be assumed in hypotheticals" - Why? I haven't actually claimed the the non-existence of perfect rationality within the hypothetical leads to any real world consequences as of yet. Arguing against an argument I haven't made does nothing.