I have a Garmin Montana and was concerned about Ascent being compatible with it.
Ascent won't sync with it, but I can open the volume and go to the GPX folder and find my track gpx files. I then drag and drop them into the activity browser. Works a treat.
Before the sync system came in a few years ago, that was the way I had to do my Edge 305 and Edge 705. When sync came in, my 705 would sync.
I don't know the Edge 1000, but can it appear on your desktop as a volume?
If so, you should be able to find your tracks and drag and drop.
Mick F. Cornwall