h7eh7he;
Your grinders should be industry models of companies wanting to break into the market. Sturdy, smooo-ooth running, and proper tool rests. As users, that's intuitive, yet beyond some companies. I sure cannot explain why, past accountants and clever marketing departments, and huge profits on import junk...
Before OSHA [which translates to "We sit behind desks, write directives to shield owners from ineptness and collect fines protecting YOU; and no we've never run that machine before, what's it called?", every shop had powerful grinders and even more powerful sanders, mostly Hammond and Porter-Cable. Possibly, some of those had 120" [304cm] belts over 12" [30mm] wheels. You could burn a big radius or polish just by varying the pressure. Those long belts were rather expensive, but stayed cool and lasted a long time.
Right after you posted earlier machines, and not finding any of the good old commercial models, I determined to follow your lead and build ground up. I have seen recently, long shaft buffers that don't have long end bells to support belt tension. Seeing your work, makes that less intimidating to fabricate.