I've misunderstood what the --road-name-pois feature did. I thought the Garmin device automatically implemented address search if the roads had the correct metadata (POIs), but that seems not to be the case.
This feature as-is is pretty useless for what Address search would be used for, there you want to explicitly search for things that aren't nearby (across the whole map). And even if you're looking for nearby things a substring search is better than having to page through a list.
Well, it was never meant to be more than a quick hack to be able to display/find road names in your locality until somebody worked out how to do the job properly. Cheap and cheerful. On the etrex, you can search the RNP's for a substring so you don't have to page through the list.
But thanks for your efforts in getting this much to work at least.
It was nothing. Cheers, Mark