This "reset floor" theory is super hard to prove and is always based on single facts or by people that are boss checkers, but hate boss campers. I think most of this is influenced in a way to force people to avoid camping. What is a FACT and is known: there are MULTIPLE bosses that are unblockable, a huge number of them can't be blocked and they may spawn in front of your eyes (there are reports and videos). However, there are some bosses that we have no report/proof of them appearing in front of a player, so MAYBE those are blockable, but it is much hard to prove. About the "reset floor" theory, it is just a weak theory. Regarding PoI, I don't have any data on them, sorry.