Welcome! The aesthetics of the Flounder intrigue me, though I acknowledge your cautions about the sunken switches and about the spacing.
One q: you say .75" spacing, but isn’t it closer to 19.05 between switch centers? Or are you talking the distance between the switch cutout edges?
It reminds me of the frog design apple tablet/snow white keyboard prototype from 1983:
Of note, the original Apple IIgs keyboard trended toward this aesthetic, but didn’t quite make it to bezel-less. Chryrosran22 reviewed this board.
I would love to recreate this using modern low-pro mech keeb hardware, with the edge-to-edge caps (I think it looks great with the stepped caps). Does anyone know if other examples of this exist, beyond the Flounder?