Please give us a regular mod colored ISO Enter and move r1 PgDn and End keys from base to numpad kit since those are used for 1800 layouts.
What Fraaaan said makes sense; I'd also prefer a mod-colored ISO Enter over an accent one (and if I wanted it, I could pick up the novelties kit). The R1 PgDn, End suggestion also tracks. Otherwise, the kitting looks pretty good to me, though I do have one suggestion:
Consider adding a R3 1u cherry key to the novelties kit. Since there are already 1u cherries on R1, R2, R4, you'd be able to fill out a whole right column on 65%/75% boards with cherries, which would look pretty cool in my opinion.
+1 for GMK