Looks like just a design to me. When vob reviewed the gt90.2 the head size was large enough to displace enough heat to run it for 15 minutes with no step down. The head on the ft05 looks even bigger than the gt90.2. I don’t see a fan being needed.
Astrolux, they don’t play.
My money on it that Astrolux will be both finished and ready for sale before the GT4 and will be more reliable than an Imalent as well.
No, it would be about the same. Similar diameter 44mm vs 46mm. Similar capacity. They probably went with 18650 so they don’t have to build new battery carriers and tubes.