(To be filed under "stuff I thought I knew, but ignored and forgot") The situation may not be quite so simple with Garmin devices that use a "locations.fit" file
On my Epix, it appears that the "locations.fit" file is only a
mirror of the waypoints/locations that are saved somewhere in the memory of the device.
That file is automatically rewritten/updated by the device.
But, conversely, the "saved location" memory is NOT affected by actions on the file, including deleting or replacing it.
As far as I am aware, a "saved location" can only be removed by manually accessing the "locations" list via the device itself.
Fortunately, there is a "delete all" option at the end of the list.
FULL "FIT" file compatibility would still be desirable, including the specifc ability to "download waypoints," which I presently cannot do via TF. It appears that simply reading the "locations\locations.fit" file would accompish this.