This functionality isn't currently possible in the current version (1.3.0) but work is underway to open up Set Light to interact with and edit as many RDM parameters (Multiverse On/Off, SHOW ID etc.) as possible.
By pulling the configuration of a fixture that has its multiverse set manually, you can temporarily hold multiverse configuration, edit it, and push it to a new fixture. You can’t save the pulled configuration though…
Saving the configuration of the device you've pulled back to your device list is definitely something we're working on for a future update. Stay tuned!
