You should consider adding R4 1.5u controls and alts along with the various other R4 1u keys as it is fairly common on the many 65%, 75%, 96-key, and 1800 style layouts to use a mix of 1.25u, 1.5u, or 1u keys. I could imagine it might be awkward mixing R4 and R5 bottom row keys for these cases.
Other than than, I’m definitely in! Have always loved the OG TA colorway, but the original GMK run left a lot to be desired.