Currently, based on the testing I've done, when converting a Map to a KMZ to load onto a Garmin device, it doesn't work. I believe this to be due to the different image formats in use by the different platforms. If I'm not mistaken, ArcGIS Pro outputs PNG image types in the KML/KMZ files produced by running the "Map to KML" tool. However, from my reading online, Garmins required a JPEG format in KMZ files loaded in as a Custom Basemap.
IDEA: Allow the option to choose what image format is used in the output file to make the product suitable for Garmins (or, a setting box that configures the output for use in commonly used devices e.g. "Garmin", "Google Earth", etc)
