Have you tried building a “GrandMA” on a raspberry pi using the onPC software? Turns out, it doesn’t really work.
Technically, Windows 10 can run on a raspberry pi, but it’s extremely slow, and unusable. There is other software such as QLC plus that will give you some basic stuff, but nothing nearly as complex as MA2.
Alternative: You could always try mini PCs, such as the Intel NUC that would run onPC perfectly fine, but it obviously isn’t as small as a pi.