Can I use it to connect 4 Rode Wirless Go, set them up via the programme on the PC/MAC and use the device as a sound source for OBS etc.?
If not, what would be your alternative / procedure?
I don't know the Rode Wirless Go, but if the receiver works via cable on a line-in, then it also works with the Scarlett. It has 4 large jack line-ins on the back, the routing and levels can be set in the FocusriteControll software.
However, if you need phantom power for the microphones, you can only use the two inputs on the front.
If you want to mix audio channels from the Scarlett with other sources and offer this as an audio source for other software, then use a virtual audio cable (VAC), I use vac.muzychenko.net for Windows, perhaps you can also do this in the meantime with OBS or similar...