Kits are looking better than last time.
Maybe consider dropping numpad
00 from the base kit, and changing the ISO keys from R3
#~, R4
\| to R3
\|, R4
<> (this is the more consistent option, and it's also more popular in sets as of late).
You can remove 1.75c spaces from the spacebars kit. This size isn't used outside of 40% boards, which this set doesn't have support for (and even if it did, these keys are only used very rarely).
Optionally, consider adding 1c and 2× 3c spaces in place of the 1.75c.
You may want to consider adding 3-key 40s support to the base kit. These 3 keys are: R2 1.75u Backspace, R3 1.25u Tab, R3 1.5u Enter
(This change doesn't affect the aforementioned change to 1.75c spaces; they should be removed regardless.)