How to delete the "empty map"?

I am using offline maps (only). I activated the "empty map" option, and the "autoload maps" option, and now if I scroll off the end of a map, where there is no map available, Oruxmaps immediately loads "no map", shows a blank screen, and it is not easy to go back to where I was. If I scroll of the map to a side where there is another map available, then a pop-up list of available maps (including "no map") shows and I can choose a map - or not. But when "no map" is the only option the pop-up does not show up and the screen goes blank as "no map" is immediately loaded.

If I turn off the "autoload maps" option, then if I scroll of the end of a map, nothing at all happens, unless I click on the globe icon and select "open map here", then I get a list of available maps for that location, if any. That may be better than the other way.

But ideally I should be able to remove the "empty map" in which case autoload will presumably pick the available real map and I wouldn't have to manually ask for it? But how to remove the "empty map"? I tried to uncheck the option to create the empty map, but it didn't make any difference, even after re-starting Oruxmaps. Looking in the Oruxmaps folder, I can't find where this "empty map" is kept.

The empty map also kept loading when I zoomed in too far, past the available layers, but fortunately there is an option in the zoom setting to avoid that.

By the way, since I have several maps that cover adjacent areas, it would be nice if I could merge them into one large map, is there a way to do that? Then I wouldn't scroll off the end of a map very often. I created each map from a digital topo map (originally from the USGS, but already processed into seamless large tiles), downloaded as a TIF/TFW pair, using OruxMapsDesktop (after converting the image to PNG).