I realize that there are a couple of posts on this subject - I would like to add another use-case in addition to EmComm (for which I think this would be VERY useful):
Sailors on yachts that rely on HF for communications could use VarAC if it gave them the easy ability to send a position report without transcribing GPS coordinates into a message. Some yachters are using JS8Call for this currently, but if VarAC had a GPS connection, it would be a much more useful tool.
there are also USB based GPS antenas for laptops. No need for NEMA network.
I would like varaac to get it directly from USB GPS with a button to send "the current GPS location"