Yes, this would be great. However, multi-tenancy might present some challenges due to the service ports required by the Unifi Controller, especially for device discovery. That said, as long as L3 adoption is implemented (e.g. via DNS or DHCP option), using a dedicated custom set of ports for each instance should work fine.
See also; https://help.ui.com/hc/en-us/articles/218506997-Required-Ports-Reference