Sorry for the issues you are having. You should be able to access the individual instruments presets with the latest version of UltraChannel. Perhaps there was an issue with the installer.

Please try uninstalling the plug-in and running the latest installer, making sure the presets box is checked – https://www.eventideaudio.com/downloads/?product=UltraChannel

The uninstaller can be found at the location below:

Windows
Locate the uninstaller at: Start Menu->Control Panel->Programs and Features->Uninstall a Program

macOS:
Locate the uninstaller at: /Applications/Eventide/Uninstallers/