I own both the PCE1 and PCE02, but rarely use them. Especially with 12-speed Di2, I only really use them to update the shifters... and only if there is an update that I really want .

If the 12-speed bike isn't connecting to the phone for some reason (make sure it's in bluetoothLE connection mode and the LED on the RD is flashing blue), then I'd rather get that fixed instead. the PCE02 is cool for troubleshooting and updating shifters, but in my experience it's easier to connect using the app - saves me the 'hassle' of taking the laptop to my bike and running the software.. and trying to read the laptop display in the sun