I have downloaded several IMG files from http://garmin.openstreetmap.nl, and they appear to work great on my Oregon 600.
I have given the files different names in /Garmin so that I can tell which IMG file is which.
There is one small annoyance though, and that is that the maps all show up as Openfietsmap Lite on the unit:
With only two I can just disable one and then find out which one it was
But with many maps it is not possible to tell them apart.
Since these strings are obviously compiled into the IMG files by http://garmin.openstreetmap.nl, it should be possible to compile custom strings into them.
So, as a feature request, it would be nice to have an extra input field on the http://garmin.openstreetmap.nl web page that defaults to “Openfietsmap Lite”, but that is changable by the requesting user to say something else.
For instance “Nederland”, “Noord-Italië”, or “Alpen”.