Roger pen is a tricky one with post-marvel aids.
If you’re using pen’s mic to talk, then that solution won’t work on post-marvel phonak aids.
If not, then it might work. And please share more about it
In marvel/paradise you can use pen iN which doesn’t have BT, or regular pen but only if you disable the BT.
For example, in older than marvel aids you’d use pen as both streamer and a mic when connecting to mobile phone. In post-marvel aids you cannot. BT in pen is needed for mic, and that one kills the one in post-marvel aids not allowing you to use pen at all.
So, if this device relies on BT features of pen to grab the mic signal, then unfortunately that won’t work on post-marvels.
However, if this device only replaces speaker part and you still use (landline) phone mic, then it might work even for post-marvel aids.
Clumsy solution for @zuikoholic
If phone accepts regular aux with mic input, then you may use headphone + mic splitter, plug tvconnector/pen/select into headphone part and plug some cable mic into mic part.
That works (I’ve tested with mobile phone using regular aux jack port)