Well Poof DOES lay down in front of the entrance's heat vent (last evening it was in front of the living room vent), so yea, I guess the warmth is an attraction.
I don't get that he's overly attracted to cat toys, though yesterday, while all three cats were in the living room (for the better part of 30 minutes), Anthony and Poof were wrestling it up. In between their many bouts, Anthony prefered Tache's old catnip mouse, while Poof discovered the pleasures of a simple foam-like ball. He also spent a bit of quality time with Tache's new octopus toy - in his near 2 hour stay indoors. Tache spent much of his time (when not jousting with Poof) just laying down observing his two buddies at play.
I guess the really good news is that during the 30 minutes of having all three cats in the living room, I was sitting on the floor near the entrance, and I CLOSED the front door!! Only once did Poof try to get outside, and when I reached to open the door, he returned to play - no hissyfit, no crying. During most of the 120 minutes he stayed indoors last night, the main door (as well as the screen door) remained ajar only around 20cm (8 inches).
All this in great contrast with the events that occured two days earlier ...