ReWire was developed by Propellerheads, you'd need to ask them if their design supports sync'ing one host to multiple targets. It's based on MIDI protocol and as that's a serial interface, it's not likely. Nonetheless contact them at https://www.propellerheads.se
As for your UC inquiry. when you install UC, you're given an optiont to choose which interfaces you want to select to install, just re-run the installer and check all or chech the ones that you need / want. If you continue to have issues, open a support request so a tech agent can help you more closely that we can here in the community area. Go to your my.presonus.com account to open a request.