Astro A50 Gen 3, switched to pc mode on the mic amp, then plugged into the switch USB. The audio is sent through usb and then transmitted wirelessly in this mode. No optical cable needed
I've tried with the three USB ports but it doesn't work with the Astro A50 3 gen, in fact I've read that it doesn't work with any Astro A50 headset (1st or 2nd gen).