That’s correct, but equatorial mounts also solve the problem of field rotation on long exposures (which, like the control problem, can be fixed with computers—-

That’s correct, but equatorial mounts also solve the problem of field rotation on long exposures (which, like the control problem, can be fixed with computers—-just stack short exposures and rotate in software). Field rotation isn’t an issue for radio astronomy, of course. I’m not sure I would say that equatorial mounts are less compact though.