👍🏻 I thought everything between the phone and the roam was done by Bluetooth apart from updates ?
That is true.
Between the phone app & the device.
(When your route is already in the app you can transfer via Bluetooth).
However, to take a gpx file
into the app requires the phone to have an internet connection.
(The route is a gpx file somewhere on your phone. It has not yet been imported into the app).
It's a subtle, but significant difference.
If you want to test this, put your phone in Airplane mode (no wifi, no data), click on a gpx file in your phone (perhaps one you've downloaded already) and try to open it in the Wahoo app. It doesn't work.
Say for example you're doing a 10 day tour and create 10 gpx files, one for each day.
If you load all 10 in the app at home (internet) no problem.
If, however, you leave the gpx files on your phone (not in the app) and plan to load each one daily you will either need internet or a hardwire connection between phone & unit.
Wahoo are aware of this for several years and have promised to fix it. Still waiting.
*My only experience is with the Elemnt. As far as I know the operating systems across Wahoo products are similar.