There are now a number of places where house numbers are well mapped and it would be nice to be able to see them on your GPS. In fact this has been a much desired feature for a long time now.
This is now possible, and has been for some time - I suck at getting the news out promptly.
It works with both polish format input files and also with regular OpenStreetMap format files.
For files in Polish format, the house numbers support is complete and any differences from what you were expecting should be reported as a bug.
For OSM files things are a bit more tricky because there are various systems of recording housenumbers used in different parts of the world, and not all of them will be recognised.
For OSM files, you need to add the
--housenumbers option to
get house numbers in the map.
Of course if there are no numbers in the OSM data in your region then you will
need to get out and map some to take advantage of this. You will need to add
addr:housenumber to nodes or polygons
representing the house.