And Ralph search is your friend, you might want to be reminded, that you were anti GaN fets way back at first, they are still the same ones buddy.You are quite correct. When you first commented that GaNFETs didn't need a heatsink in an evaluation circuit, I didn't believe you. But I followed the link you provided and promptly went down the rabbit hole learning more about it. So you can rightfully take credit for that.
What is puzzling here is that even though you knew that bit about heatsinks, most of the rest of it is a complete unknown to you. For example, if I were to ask you, 'what is the **main** advantage of GaNFets?', what would be your answer?
If you answered 'speed', you would be incorrect. GaNFets have lost their speed advantage over MOSFETs, which have continued to improve since GaNFETs were introduced.