Stereo mode without connect app

Is it possible to activate the stereo mode for two Charge 3s WITHOUT using the connect app? Maybe there is an undocumented button combination?

I do have the app on my phone but I’m also using them on my tv by connecting one of them via cable to minimize audio lags and the other one via bluetooth to the one connected to the tv. It’s quite a hassle to make them play in stereo mode by using the app on my phone. I installed the app on my tv as well but it doesn’t work on it. And even if I turn on stereo mode by using connect on my phone they sometimes refuse to play the tv sound in stereo.