You replied yourself: "yes
the board still works but there is no advantage"
You just discovered that the mast position is irrelevant once airborne. This is what I said!
(And if you had tried it with some strong offshore wind, you would have seen the advantage of not having a big chuck of board far forward, but I digress)
Now, if you actually read what I write again and again, the advantage is when
PADDLING WITH A PADDLE ON A SUP. This way you do not have to move your feet around and risk misplacing your front foot (which I think you agree is key). You have the same feet placement paddling and flying, which is a huge advantage when learning. Plus it helps using straps, which is also an advantage.
So [1] no disadvantage when flying, [2] huge advantage when paddling... the choice is quite obvious.
PS: Xavier SUP video was on his 3rd ever time on a foil... thus it shows the advantage when learning.
An example of the "awkward dance": look at all the movements (at 0:07) Robert does with his feet when transitioning from paddling to flying... when beginning each movement is an opportunity for disaster, only with his hundreds of hours of experience he is able to manage this dance... My point is why suffer and take risks (misplacing feet ==> board rolls and you fall on the foil) where there is a safer and easier method?
I do not know why you are so aggressive. I understand you offer a commercial service with lessons, but I don't, I have no foiling school in OZ competing with you trying to lure away your customers. I present in this thread a method that works for me (who doesn't own a boat) and many others, you have your own method which is different (maybe being far aft is better for towed sessions?) and I guess successful too.