Can my phone stay in my pocket while I use smart glasses?
Yes, for features designed to operate through a locked, connected phone. But a feature working while its companion app is open does not establish that it continues after the phone locks or the app becomes inactive.
The app still has a job to do
A pocket workflow may need the phone to receive an event, perform permitted background work and send the result. We would judge that complete sequence rather than the Bluetooth icon. The operating system and the app's implementation both matter to whether the work continues.
Start the intended feature, lock the phone and use it again after an idle period. If it only works immediately after the app was open, the result is different from dependable pocket use. Record that distinction with the phone and app versions so it is possible to investigate rather than merely repeat the failure.