Nice kitting overall.
I think the F-row setup with alpha-colored F5–F8 and F13 is going to look weird. I suggest either dropping alpha-colored F keys altogether, or changing them to the standard color layout (F1–F4 alpha, F5–F8 mod, F9–F12 alpha, F13 mod).
A useful extra key to have in base would be a R4 1u key with a generic legend, e.g. Code. This key would help cover several oddball layouts, from 60% up to 1800/CP, and even some 40s.
Speaking of 40s, consider adding a 40s kit. You can look at sets like EPBT Grand Tour, EPBT Be The One, EPBT 6085, EPBT Skadi as a reference for this kit, as well as other kits.
Consider adding a R1 1u = key to the numpad kit.
You can remove the second copy of 1u space from the spacebars kit (it's only used by 40s, and the 40s kit should contain its own spacekeys). In its place, consider adding the other variant of 6u space, such that the spacebars kit contains both centered and off-centered stem variants.