Ok, I've been able to load caches into my Crossover as Waypoints in Outdoor (in addition to POI's loaded in Vehicle Nav) two times now and it's worked both times.
You need to make a file with a UTP filename extension. To do it, use GPSBabelGUI (for some reason it doesn't work using GSAK).
Open the program and under Input in the Format box select GPX/XML, in the File box type in the path and the filename of the gpx file that you want to create the .UPT file from.
Under Output in the Format box select Magellan SD files (as for eXplorist), in the File box type in the path and the filename of the upt file that you want to create. Note that the filename and the filename extension both need to be in capital letters. Select let's go and the file will be created.
Copy & Paste this file onto your SD card. Insert the card back into your Crossover, turn it on, press the reset button on the left hand side after it powers up. When the GPS is ready go to Outdoor/Options/Waypoints Options and choose Clear Waypoints.
Then scroll down to & choose Import Data. Select the file that you put on your SD card. The file should load and you should have the Waypoints loaded with their cache name (not their description) in Outdoor under Waypoints.