** You can add as many as you have panel space to accommodate. You'll still
be limited by the 50 amp feeder and main

I guess what I'm trying to ask is there any restriction as to what
size cabinet I can put in?
I am limited to space, but if I could , is there any code violation if
I put in lets say a 20/40 panel?
I thought the main service dictates how big of a panel you can put in.