Hi Shane (and All),
I enjoyed reading your post and agree to your findings so here are my experiences:
I started 2021, NP 800 foil, with a FanaticFalcon136, then went on to Starboard iFoil100 with the alu mast, now FoilRace100 (extremely sensitive to damage). I have the 1000/800/650 foil set on 115+fuse, firstgen carbon mast and ifoil carbon mast. Stepped up to 575 evo and 420 SLR/210 evo2 rear. I'm not racing but like to go fast, early and so on. I like a challenge and a good, hard workout. I am not scared about crashes.
I hated not being able to get up while my mates did, got the Superflyer 1500 last year which was a massive change. Early flight, almost no sail necessary, but massive lift, maxing out @ 19kn. That speed was reached very easily and not enjoyable anymore. So the wind range is quite small. However, the low stall speed allowed high flying gybes (without freaking out) so I could improve my gybing. (So sometimes a different kit is better).
My handling of less and more wind has improved only very gradually over time. There was a recent jump however, which had to do with trim. I was able to change the mast to a more forward position, which allowed to sail faster. The confidence is there now to lean the rig to a front position to accelerate and charge better. It feels like the 23 kn is nothing special anymore.
At the same time, my pumping technique has improved so I have a fighting chance to keep up with the pros here (Bob is a real challenge, haha!

).
So for take off and speed, noticing something was wrong was not enough. I needed to get the feeling WHAT was wrong to improve the trim which took me a lot of time. That could not be done by simply buying new kit. Additionally, it required me to change all kinds of things instead of just enjoying a ride. I would recommend to a newcomer to go through the pain of changing angles, board trim, sails and sail trim etc. to get there earlier than I did.
Another way of improving is taking a video of yourself. I was frustrated about my gybing and a friend of mine told me I sheeted out to early. My first reaction was: What's the point to keep on the rig when there's no power in it anymore? I went to the videos on Instagram and YouTube and found that the pros really did it differently. I could SEE what I was doing and compare it to what they were doing differently. The little difference was to lean the rig leeward very early and my gybing went to another level almost immediately.
Still, there seems to be a speed limit set by the kit used. For me in the comfort zone it's 21kn for the 1000, 23kn for the 800, 25kn for the 650 front wing. Does that matter if you're not racing? Of course, haha!
Hope I could add a little value to the discussion.
Cheers,
Rainer