Hey...I had a customer that builds control systems for industrial food processing (ovens and blast chillers that use conveyors). The only trick is that all the motors should be identical and to add 10% extra current capacity over the total (because large motors have higher inductance which acts as a current limiter), also individual overloads. They regularly used >10 motors on a drive. Never had an issue. His supplies come from
Automation parts, so far it has been good words. I do not know if there is a theoretical limit to the number of motors as long as the aggregate current draw is <90% of the drive’s output current capacity.