After looking into it a few months ago, there has been demand for replacement screens for a long time for the Machinedrum, Monomachine, and Octatrack MK1 & people doing the mod (they all use the same display type (KS0108), but possibly different voltage? not sure).:
A while (5-10 years ago) others were able to get their hands on VFDs (vacuum fluorescent display) that use the same form factor & display protocol (KS0108). VFD is very similar to OLED in ghosting, contrast, and brightness.
Unfortunately, I contacted the manufacturer of these displays late last year and they have unfortunately skyrocketed in price ($350+) since these posts making them cost prohibitive.
For reference, these pre-modified VFDs used to be sold for sale online for a little under $300 here and other places:
https://reverb.com/item/3344502-vfd-display-upgrade-elektron-md-mm-octatrack
Here also another guy that has made and is selling higher quality LCD panels, but they are still LCD.
You can see pretty clearly here his white panels are in fact LCD:
Currently I think most people default to using these KS0108 displays as they are cheapest right now but they all are still just LCD panels with bad viewing angles & ghosting:
https://www.ebay.com/itm/291836099801
Anyways, some info on the demand if you’re curious. I imagine designing a niche product like this is a big time commitment. But I think there would be a small market for it.