Presumably these are known about?
the twister has been on my wishlist for some time. pretty neat kit!
That’s a lot of work to machine up a box for 64 controls at home.
I have seen little game controllers that sticks to the face of a tablet, perhaps the right rubber button array can make a tablet more consistent control than directly touching.
Funny, My Avast virus tool believes it’s a Phishing site.
3D print it… the 8x8 (250x250mm) can be printed in 4 parts (even two, on a slightly better-than-average printer)