I suspect that the details of this feature will become more of an issue as folks may be wanting to select and export areas (especially KMZ uploads) that do not correspond to screen aspect ratio. I hope to playing with this more soon.
Yup. I am starting to work with uploading KMZ files to an Oregon and would very much like to be able to accurately select the imagery to be uploaded with a user-drawn box on the screen.
The KMZ upload capability of TF is impressive and relatively seamless to use.
On the other hand, Garmin seems to have crippled the usefulness by (1) imposing severe limitations on the amount of raster imagery that can be uploaded and (2) preventing the user selectable choice of two different tilesets that cover the same area (like topo and aerial imagery).
For example the limit is 100 "tiles." I uploaded the 2M Topo imagery for a local area of roughly 10 x 7 miles. That was only 15
MB worth of data but used up
54 tiles.
In the space remaining I can upload some corresponding aerial imagery, but, as far as I am aware, it is not presently possible (on an Oregon 300) to switch between topo and aerial imagery covering the same area.