Forgot to check Doepfer. It’s great that Dieter is doing something different, and for that I salute him and encourage him.
The CTM64 is not only available now, you can even buy the separate parts and piece them together as needed. It handles up to 64 button inputs.
If you want to make an alternate controller, this looks to be the least costly way. The CTM64 main board is $135 from Analogue Haven. The 8×8 square matrix button board is 125 euros direct, ask Analogue Haven if they have them. You can always create your own. I’m thinking of getting a CTM64 and designing a PC board for a keyboard with a staggered key arrangement, using these tact switches. Caps are available for them—in 6 colors.
Now, if only Dieter would put out that touchplate keyboard he keeps showing……