i am guessing you must live in a place with little to no sunshine ... that clear plastic covered pocket on the Ducati tank bag is only good for cooking phones when the sun is out. i keep my iPhone inside my bike's Ducati tank bag and powered up with a USB charging cable. although, i just purchased a quadlock for the Multi, and will run a USB cable out of the Ducati tank bag to charge the iPhone.
I have the quad lock with the Evotech GPS mount for it, absolutely brilliant bit of kit. With the option of Google Maps and Calimoto apps for navigation (the latter being bike focused), there is absolutely no need for a dedicated GPS like a tom tom.
perhaps no need for dedicated GPS where you live/ride ... but here in California and the western US states, there are LOTS of areas with zero cell coverage. sure, once can store maps in memory on a phone ... but call me old school (well not too old school, as i don't carry paper maps on rides) i like my Zumo XT as a failsafe.
I found I couldn’t see my phone display in sunlight, making it no good for navigation. I agree with the comment above as well, if you put your phone in the pocket on top of the Ducati tank bag the sun will cook the phone.
Huh, I know some areas were bad but I never had an issue with google maps, but I see your point. The only time I had any form of issue was a drive down from San Fran to LA, on the 5 I had a couple of times where it had zero signal. I moved back to Europe at the start of August and I'll admit, cell coverage is much better. I've not had an issue in direct sunlight, but mind you, the Note 20 ultra has a very bright screen. And agree, I'd not put my phone in the tank bag personally, that's asking for trouble. Maybe with the screen off to charge.