own WMS/WMTS map, with offline caching

Hi,

Would it be possible to have an additional option to use a user-specified map, delivered by WMS/WMTS. It can also be the typical xyz format which is the same as for the mapbox service.
It would also be nice to have several, so we can switch trough depending on the situation I like to use topo or ortophoto maps.

It would be exciting as our national service provide high-quality ortho maps and reliefs, which are of much higher accuracy as google and co.

Thank you very much