It is interesting to read the approach that was taken, particularly with regard to mapping, as this is the area where in my view Karoo has an unfortunate design flaw — which is why I’m selling my unit.
The forums have a number of posts about the inability to download the maps for long routes; others have complained about the need to highlight multiple areas, etc. I wanted to use my unit as a backup for my race Norway — Spain in June, but could not as it provide impossible to download the tiles. Ended up with OSMAnd+ on my cell phone as the backup to my Garmin.
This is in stark contrast to apps such as OSMAnd+ which allow you to simply download an entire country’s open street map and be done with it.
The tile approach’s problems were highlighted to me just the other day when I was out for a ride and I reached the end of where the tiles had loaded so I was literally ‘off the map’.
The hardware is great, but if you want hassle free and reliable mapping and navigation it still has a loooooonnnnngggg way to go. While you post is optimistic about making it happen, I can’t see it if you persist in this approach of using the tiles. But all this has been said on the forums :-)