Thanks! There are all sort of hidden gems in this app! Just takes a while for a Locus newbie to find them.
Unfortunately, BaseCamp won't open the Locus export. However, the Garmin 64st opens it just fine.
And my wife's iPhone using Cachly opens it just fine. This will work!
This lets me do the equivalent of a Pocket Query with my phone while in the field, and then send the GPX to the Garmin and my wife's iPhone app and we're ready to go - no computer needed. It's come in handy several times when we were in the boonies and we saw an interesting area to explore/geocache.