You should be able to load anything which is in an acceptable Garmin format (emphasis on Garmin) and for which there is room. Room includes both physical space on the device or SD card and limitations on things like the number of map segments.
That said, displaying the map is one thing. Taking advantage of all the features of the proprietary Navionics maps is a different thing.
Edited to add: I have no personal experience with this. Before spending money on the maps, you should probably ask the question via a support ticket.
