Updating the maps was an exercise anger management, involving setting up accounts and syncing data to their cloud (why would I want to do that to update a map???). The maps turned out to be woefully out of date even after updating.
I managed to flash recent OSM data to one of the units, but the map rendering is so awful, cluttered, and so slow that this turned out to be just as pointless.
This is something that just can't happen for this kind of use case, and the fact that bugs like this repeatedly happen with Garmin is mind-blowing to me. This company makes glass cockpits- if you ask me, they need to borrow someone from that team to show their consumer electronics team how to test their product and have a sense of urgency when things break.