The ios app is the only way that I can command the headphones to connect to a second device. When 2 device mode is going on, I have no idea what the connection is like in ios but Linux plainly tells me that it can only do SBC and SBC-XQ. When I turn off 2 device mode, and pair it again, LDAC is finally offered. My 1000xm4 doesn’t offer AAC, I don’t think I have anything around that sinks AAC. My Steamdeck can work as an Opus sink lol.