I thought I may use a Bluetooth dialer like one of those listet on the page below. That could be practical while on the go. The worthy Librem 5 could stay in a safer place like my messenger bag. I don\t have to pull it out and avoid the risk of dropping it.
I could use Bluetooth in ears. Unfortunately these are tricky to use, because most of them are controlled by touch surfaces nowadays which are also often bounjjjd to multiple functions. When the phone rings it might very well be, that I hurry to pull them out, put them into my ears and answering the call without accepting the incoming call to early or cancel it entirely by accident.
I think this is possibly easier with a mini-phone-like device.
I think chances that it works are not that bad for incoming calls, but what about outgoing calls? Those devices have a contacts function and keys for entering phone numbers. They can also be used as GSM phones. I don’t know if the contacts function and the numeric keys can be used to choose a contact from the Librem 5 or make the Librem 5 dial a number that I type on the dialer device.
Not sure on which levels both devices have to cooperate. Bluetooth obviously. I guess the calls and contacts apps. Some dialers can sync contacts. Not sure if both devices couple like a keyboard- like input device. Audio must be streamed. Sounds complex alltogether.