Why not just run your own GB? This is not meant to sound antagonistic, I am genuinely curious.
(off topic)
I previously considered running a mono-coloured matte-SA IC through SP's new system, called "Rock SA", a gray-colored set, simple because it has just one color and many extras to satisfy many people, but since I moved on from D/SA's, I left the idea behind too
At this point, If I was to run a GMK GB, it would be a GMK Dolch Add-on with rainbow coloured modifiers (basically a unique color for each modifier that I've been obsessed with lately) - and some edge keys that cater to edge needs, so it wouldn't be a full set, as I find the Dolch colorway pretty satisfying, the Dolch is the colorway to settle with IMO
But, I don't have time or energy to run a regular GB where you have to handle all the money and shipping, I also don't think my tastes are near-universal, for a GB to be successful, it has to gather a significant following at an affordable cost, I tend to keep the costs high (at 250 MOQ, a GMK GB is quite the challenge, best case scenario I would reach 50)
Comparatively Massdrop supercharges GB's into reality pretty quick, however, it obviously burns the engine too, almost everytime
Tho, If I was to run a GB, I would just adopt a proven keycap selection like one of Ivan's and only extend on that set (that's what I don't like about GMK TA, it's regressive, like I mentioned earlier it's just my opinion, don't take it too seriously)
What would be great is a MOQ of 1 with keysets, these selection related discussions would be over fast :)
(I rarely see SP one-offs, they just get what they want and not babble like this, like a boss, but with GMK, you would likely need to be a billionaire to do it with 250 MOQ)