BakerBoy
It's all small stuff.
JB, I have long since left the GPS out of the pairing with my RT. Yes, it can be nice to see who's calling, but other than that, trying to manage calls through the GPS is a PITA since it's a long reach to the GPS with my short arms and the functionality doesn't interact with the Wonder Wheel.
I pair the 20S to my phone as a mobile phone, then pair the 20S to the BMW also as a mobile phone (not a second mobile phone). Apparently the bike can only pair as A2DP and somehow this approach works. My phone is an Android (S7 Edge) so I simply press the phone button on the 20S, say "OK Google, call Baker Boy" and voila, your phone is ringing. I can't ID incoming calls, but it's easy to hang up! I rarely have had an issue with the audio not coming back after a phone call or Google interaction, although I recall that happening a couple times when I asked Google something it couldn't figure out so it kept searching... Turning the 20S off and back on solved it.
Most of all I like the 20S for accessing audio sources from the BMW audio system because the 20S has an audio out jack. I plug in my nice Klipsch or Shure sound attenuating earbuds and get way better sound quality than helmet speakers. I'd wear ear plugs anyway, so inserting earbuds before putting on my helmet doesn't take any longer and I'm not hardwired to the bike. I get longer battery life on the 20S since the drivers are so much smaller in the earbuds. I have practically my entire music collection on a tiny USB thumb drive (like this) plugged into the USB port in the (sadly small) right fairing pocket. I can set the system to play random tracks, a certain artist, album or artist, etc. Plus the BMW audio has AM, FM, Satellite (which sucks in heavily forested New England), and Weather Band. And I can still connect bike-to-bike with the 20S.
Another advantage over pairing with the GPS is that music volume drops but doesn't cut out entirely when a GPS prompt comes on. That's much more pleasing to hear than the abrupt cut out of music when a GPS prompt comes on, as happens when paired to the GPS.
I set my phone with call audio enabled and media audio disabled. That allows phone calls to route through the 20S, and all audio sources from the BMW (music, radio bands, GPS prompts...) to route through the 20S.
Thanks for the info Bones. I had a longer reply written, but lost it to one of those IE Site Security popups. Now that I've dropped the phone-to-GPS pairing, things got along much better. My 20S is paired to the iPhone, and the 20S is also paried to the bike's Rider (first) BT connection. Nothing is connected to the bike's Passenger (second) BT connection. I too use a 64GB USB mini drive full of my music, with Etymotic or Shure sound isolating earbuds driven from my 20S. But I've added an inline volume control between my 20S and the earbud jack as it is too loud otherwise. Maybe the 20S firmware update and reset to factory defaults will obviate that ... and pie. I'll try tomorrow.