This is as far as I can put it into fullscreen, there still is a boarder between Dex and the app, I assume that is fullscreen mode? However, as you can see, I get double pointers.
I pressed, clicked, held down the mouse wheel, but its still the same, one small pointer, and one large pointer. I even switched to a wired mouse, as the one I am using is wireless.
I don’t have any mousing issues just using Magic DosBox on the phone, just in Dex Mode as far as I can tell.
Also, thank you for the link, that worked out perfectly for me. Now I will have plenty of space to fill with needless programs, lol.