Does a driver or module for RS232 protocol (over ethernet) or IP control for control systems like Crestron, Savant, Control4, etc. exist?

No, although we do receive this question from custom installation firms from time to time. It is something we might be interested in supporting in the future, but we do not have a timeline for this at the moment. The vast majority of Aurender products are used in single/dedicated listening room scenarios.