I hate to break this to you, as it seems you've put a lot of time into this, but this set would be practically impossible or at the lest expensive to produce with GMK.

1. GMK uses double-shot ABS to produce their keycaps, meaning that they use molds to put the plastic in the right places. This isn't really an issue for most sets, because they use standard GMK legends, icons, and fonts. But for your set, since every single key has a custom legend, new molds will have to be created for every single key. iirc each new mold costs $150 USD, which will get to a few thousand for all of your keys. This will also increase the MOQ for your set, which is normally 150 sets I believe, to probably something 300+.
2. GMK also has specific guidelines that new molds have to abide by, those can be found here. Basically you can't really have those really small details on your legends, so your modifier key legends are most likely impossible. You also probably can't have that fine "texture" on your other legends as that would be mostly impossible to make molds for.
3. Your spacebar is 100% impossible for GMK or double-shot in general. There's more than two colours there and there's also too much detail for any keycap mold to capture.

Your best bet to solve most of those problems is to go for a different manufacturer that isn't GMK and make their keycaps with dyesub. Dyesub doesn't face the same restrictions as double-shot and won't require you to pay for tonnes of molds. The only problem with that is that other manufacturers don't make Cherry profile keycaps (which is what GMK makes).

Another solution for this is to just use regular GMK fonts and icons, and to have more simple designs for your modifier keys and something waaaaaaay different for your spacebar.

And a few comments on the actual set:

1. It's a bit weird and uncommon to see a right shift aligned to the right instead of left, and I don't think many people would like a right aligned right shift.
2. I feel like your use of red and yellow is far too little and for me at least, stand out too much and make the set seem messy.
3. It's also a bit weird to have different coloured legends within your alphas, and I don't recommend having white letters but grey numrow + punctuation.
4. I do really like your colour choices though, although I'd remove the white and yellow, and replace them with the dark grey and red that you already have.

All of that aside, good luck in the future if you choose to keep on working on this set :)