How about a universal virtual CD-Rom board.
It would take the motor voltages of various CD-Rom designs of the past
as input and output as if it where the laser unit the system expects.
This could be a solution for all (obscure) lens based systems at once.
yes? no?.... i'll let myself out....
That would be a nice solution, but I doubt it would be financially viable, as you would buy it, put it in one console (say a Sega Saturn), and then the extra hardware it contained to make it work on a dozen or more other consoles (say the Playstation, Neo-Geo CD, etc) would never get used, so you'd be paying for hardware that you'd never ever use.
If you have one flash cartridge* that worked on all cartridge based consoles, then you might get your money's worth, since you could just remove it from your SNES, put it in your Megadrive, play some Megadrive games, then remove it and put it in your N64 and play some N64 games, etc.
But with an ODE, you mostly have to solder it to the console's board, so most people wouldn't be happy, say, unsoldering the ODE from their Playstation and soldering it to their Saturn when they wanted to play some Saturn games.
You're right, though, a universal ODE, if it were priced reasonably enough, would be brilliant. I just don't think it's possible to bring the price down that much, especially given how few people, relatively speaking, would want one. If they could be sure of selling ten million of them, then I'd imagine someone could make one that was attractively priced, though.
* I know, a universal flash cartridge would be too expensive, and have a dozen different ports meaning it would be big and uncomfortably shaped, but you get my point.