Ah. OK. Yep passthrough via PULSE know works. Thx.
Update: RA starts up and has audio. ES and FF are not starting up properly and seem to hang somehere (Sway background is visible). Are there any PA related settings I need to adapt or remove ?
N64: Still some crackling sound with Doom64, while F-Zero X and Mortal Combat4 seem ok. So, not a general problem, it seems.