Disagree with number 1, a sh!tload of windsurfers get a SUP for the days that it is too flat to surf or just too windy to surf and not enough to windsurf. Having a mast base insert was a major selling point for me as I have basically a triple use board now.
Taking a router to a brand new board is good for the soul and makes one look hardcore

but not good for resale value.
Agree with the handle on my JP - lurrverrly.
The addition I want to see: breather plugs.
I don't care if the (large) Yank market does not like them cos they forget to do them up, or it adds $1 to a board, or if a bloke who lives in a steady 20 degC climate thinks they are of no use. I live in Australia.
I put a SUP with a styro core in a car that is 60degC PLUS and it may go pop. Give me a fkn breather like windsurf boards have had for 15yrs - or give me a 10yr warranty against delam.