Geotag Photos: GPSMAP 66sr Geotagging sync for Panasonic LUMIX G9M2 camera

Just wondering about practicality of developing a direct connection between my Garmin GPSMAP 66sr and my Panasonic LUMIX G9M2 camera - specifically to geotag photos as I snap the picture.

The G9M2 has the ability to automatically geotag photos using a Bluetooth connection to my iPhone - but only via the LUMIX Sync app. This is a nice feature, but there are some limitations - the most difficult of which is the requirement that the iPhone LUMIX Sync app must be running in the foreground on the iPhone (dunno yet if the Android version of the LUMIX Sync app has the same limitation). When the LUMIX Sync app is running in the foreground on an iPhone it prevents the screen lock/timeout feature (like a navigation app) - so it's always running and ready for the G9M2 to establish a connection for sync actions (including geotagging). However, it really is not practical to always leave the LUMIX Sync app running in the foreground all the time. For example, when I'm on longer hikes...unless I bring supplemental power for the iPhone. I understand this is limit is really an iPhone limitation. I haven't tried the Android app, yet. But that's my next step once I acquire an Android phone of some sort.

Anyway, it would be great if there were an app or widget that I could install on the GPSMAP 66sr that would automatically accept/restore the a Bluetooth connection to the G9M2 and negotiate the exchange of GPS data when requested.

I'm guessing developing a geotagging app for the GPSMAP 66sr is not really practical and my best option is just to bring a battery for the iPhone on longer hikes. Or maybe the Android LUMIX Syntc app will allow the app to run in the background for geotagging...

But I thought I would ask. :-)