Firstly, I think this is a really cool set that I can tell you have put many hours into and are passionate about.
From what I can tell, it seems like there is a mixture of intentions here of OP wanting to be adventurous/imaginative in kitting choices and the community feedback wanting OP to be much more practical in kitting decisions. Being innovative as a keyset designer is absolutely okay and necessary in my eyes, but not at the cost of real compatibility (something I learned the hard way as well).
Honestly, some sets can get away with being adventurous because the risks taken in weird key inclusion/theming are still functionally practical and don't undermine the exclusion of other keys (40s support, accent ISO, accent arrows in base in this set). From personal experience in designing a set that is trying to do some weird stuff, I understand why OP is protective of his inclusions and also understand the perspective on why the exclusions are not fair/practical.
I think there are two decent compromises here that would appease both sides (in order of which I think is best in the present situation):
1) Switch to PBT - From my perspective, it seems that the kitting decisions you want to take are almost better suited to decisions one would make in the context of a dye-sublimated set. While most of this would be reverse dye-sub, I think this is seriously a viable option here especially with better PBT options opening up in the last year. MilkyWay has good reverse dye-sub even though the alignment of legends is off a bit atm, but the latter can be fixed rather easily. The shift to dye-sub would also allow you to move things around more easily; main example being that you could put 3/4 key 40s support in base and move the roman numeral keys to the novelties or macros kit while keeping everything fairly affordable on all accounts. I also think that a set with this many kitting liberties could really suffer in the current GMK climate as well (not knocking the interest you are receiving or your work at all here, more just speaking on the current state of the market).
2) Stick with GMK - Put 40s into the base kit and move the roman numerals to the novelties or the macros kit. The number one goal should be to get the base kit to MOQ, and I would be worried right now about the pricing of the base kit along with the controversial decisions being made in this current GMK climate. This would dramatically reduce the cost of the base kit and possibly allow for other inclusions like accent ISO or accent arrows in the base kit. The novelties kit currently requires 20 new molds, while the macros kit requires 12 new molds (not including the redundant keys from the molds required for the roman numerals currently in base). To me, the macros kit seems the better option here for a couple reasons. First, you would be condensing all of the interest in the roman numerals into this one kit if they were all in one place. I think this is less risky for the set as a whole, as you would only jeopardize one kit making MOQ rather than the whole base kit itself. Second, you would also be condensing the use of the same molds into one kit and incentivize the macros kit to be made at the same time. This is a minor benefit but still worth noting. I think if you are worried that the roman numerals wouldn't make MOQ organically as a child kit, I'm not sure how you can have confidence that the macros kit, as is, will make MOQ. Especially given that traditional macros kit only make MOQ if the set is extremely hyped or guaranteed buyout, and that your macros kit not only features nontraditional legends that require new molds but also has extra 'novelty'-like keys (objectively). Both of these increase the cost of the kit substantially.
-- side tangent on the red accent arrows: there is a knock-on effect if roman numerals are moved out of the base kit that would favor the inclusion of red arrows in the set. The tan accent arrows can move into the base kit from the spacebars kit, which would then make room for red arrows in the spacebars kit.
I am absolutely not telling you what to do here, just taking a civil approach at trying to help and provide you with options. I hope you consider my feedback and even if you don't, GLWIC/GB.
There's probably a lot I missed, pls forgive.
