100% agree with what you said
@jeroensurf, that's why I've held off on the cedrus as it's a fatty, but guys use it at my local and say it's good, plus they can ride any brands with an adapter.
I'm 100kg+ on gofoil atm (I think 14mm thick and 127mm chord) and sometimes when winging the swell is at a funky angle to the mast you can feel the drag and it's basic a flat piece of carbon no taper at all.
I'm hoping Cabrinha comes out with a stiff mast next January as I think they are on the right track, but stuffed up with v1 by the sounds of it, being a noodle, personally I've never ridden it, but from forum feedback I'm not going to bother. their h-series foils look money, haven't tried them yet.
I think slingshot have a strong mast (funny foot though), UniFoil is apparently strong too in v2.
My moses mast is great for kiting, 91 cm (13.5mm thick, 1.693 kg) and can go over 30kn on foil with it, I jump high, do back flips etc, but when kiting using a super light weight board 100cm and always have lift from the kite so the dynamics are different. I wouldn't dare use it with my heavy wing board, it would be noodly as $##@! And kiting you don't want a heavy mast to jump with.
But there's more to just a mast imo, it's the whole package, do you like the foils of the brand you ride, can you use an adapter, use different tails easily, does the brand release new foils often, is there a good resale value if the foil you thought would be good turns out to be a lemon?