OK Dommo - I'll take that
**** slap! I was speaking less precisely than the detail you've gone into - I certainly wasn't trying to be controversial!
I conflated volume and stability which is only partly true due to width, like you point out. Both are needed for stability.
On length... Again not trying to be controversial because what you say is right but in displacement mode (not planing) top speed is determined by waterline length - that's not disputed. A longer board glides faster than a short one. Assuming no pumping of the board (as a beginner won't be) a longer board will get up to foiling speed faster than a short one especially if using a smaller foil which needs higher speed to reach lift off. If I'm wrong on that then I'll happily stand corrected, but the physics doesn't seem illogical. It might be that most beginners are using bigger foils compared to me that this issue is not as I experienced it, as take off speed is lower.
In marginal conditions, I focus getting the board speed up, give a couple big efforts in pumping the foil, and that unsticks the board and off I go. I don't think I'm getting much forward propulsion from the board pumping but its just enough to get the board up and released to enable acceleration from the wing. The higher speed I can generate before pumping the board the easier it is.
All current foiling boards are designed assuming that they will be pumped to help get on the foil and as such will want to go short as possible to aid that, and reduce swing weight. Beginners are generally focused on pumping the wing rather than foil.
I think that's all you called me out on. Can't see all you wrote.
Your turn! ;-)