The REAPER profile for UF8 and UF1 provides control of solos, mutes, faders, pans and automation modes. This is what the in-built REAPER MCU implementation provides access to.
REAPER users wishing for deeper control might want to explore the various 3rd party scripts/user plug-ins.
These 3rd party scripts install extensions or ‘user plug-ins', many of which allow deeper MCU integration and access to more V-Pot assignment modes.
MCU Extensions for REAPER, available on the internet:
Please note, SSL are unable to provide support for users installing these scripts and how they may interact with the UF8 REAPER profile.