I'm on a Keychron V3 base with Gateron Brown switches and PBTfans Dolch caps. I have some foam fillers in the spacebar, but no hardware mods otherwise.
I went with it for similar reasons: programmable + 3 or 5-pin hotswap + TKL + normal profile gave me a lot of flexibility to try different things.
I'm especially happy with the keycaps I settled on. I realized almost immediately that Keychron's stock "OSA" caps weren't for me. Next I tried an ABS shine-through set, which were too hard to read with the backlight disabled and started to develop shine very quickly. PBTfans seems to hit a sweet spot for me: nice texture, comfortable Cherry profile, PBT material doesn't seem to wear too fast, and doubleshot to prevent the legends wearing down.