There is directory \oruxmaps\mapfiles\customonlinemaps where we can add custom online maps, but they have to be all in one file named onlinemapsources.xml.
Problem is if user downloads map info from several sites he then has to manually edit and merge content on each update.
It would be more practical that we can have more files in this directory and Oruxmaps loads (and merges all of them).
That would also allow mapservices to offer for their users to download {mapservicename}.xml that would contain online map source configuration for that specific service. User would then just save that in \oruxmaps\mapfiles\customonlinemaps and get it working instead having to mess with editing and merging XML data.