Huh, a Windows VM might be a brilliant solution to this.
And now I'm wondering - could I maybe use something like Bottles or Wine to install the Windows software that handles Sapphire LEDs? Or would these apps not see the dGPU when virtualised like that?
Ooh, nice one! I'll need to have a look for some detailed manuals/design diagrams of the Sapphire Pure, see if it's mentioned.