I have some suggestions about the novs:
_ R1: Great
_ R2: I think a mod color novelty for Tab key is enough, I rarely or never see anyone using an accent novelty for it.
_ R3: The alpha color novelty "Hg" seems redundant, I wonder where it will fit in popular layouts. Also, this key is repeated from R1 so I think it's better removed. The chemistry bottle also is repeated.
_ R4: The 2 R4 1u mod "Hg" key are also repeated, please consider moving the chemistry bottle from R2 and R3 to R4 to replace these 2 "Hg", then turn 2 nav columns to 1 nav column. The 1.25u mod Skull&Bones are also repeated from R1, in this case I suggest replacing these 2 with the 1.25u version of the 1.5u key on the right (you'll have a pair of 1.25u and a pair of 1.5u with the same figure)