Some notes for details:
* Do design struts inside the keycaps at the right height to make them compatible with silencing O-rings and QMX clips. SA and DSA don't have this.
* Make sure that stabilised keys are thinner in the right places to make them compatible with different Costar-style stabilisers. Some original Cherry keycaps have problems on some keyboards. Many later keysets like Leopold's thick Cherry-profile do this right.
* Injection nipple is least visible if on the bottom.
* Keycaps that are shiny on the sides (regardless of texture on top) look the most vintage-like. I suppose this might be mostly a cost-issue though.
Is DSA really lower than cherry? I Always got the impression that cherry was lower, or at least most of the rows. Is it feasible to do a sculpted cylindrical keyset with a lower profile than cherry?
Cherry's home row keys are lower than DSA. Other keys are higher.
DSA is about as high as OEM profile home row.
Regardless of the ultimate profile that is chosen, it would be great if there were convex spacebars for the various split spacebar sizes: 2.75u, 2.25u, 2u, 1.75u, etc.
Personally I would like the bottom-row modifiers to also be convex, because I tend to press both Alt keys with my thumbs as well.
I am also a member of the school of thought that the angle of the ZXCV row should be larger than uniform. (DCS better, Cherry profile worse. Preferably the switches on the ZXCVB row should be angled more, but no Cherry MX keyboard is done that way)