Given the arrow keys no longer move the ego, and it's very hard to click right on the edge of the window to move the ego to the next screen (unless you lock the mouse cursor in DosBOX, but even then), what's a good way to have easy north/south/east/west exits from a screen? I would have thought there might be some "border" property that lets you inset the edges of the screen a bit. I didn't see one though, and the code that detected the ego and moved to the next screen was checking against hard-coded numbers.
It wouldn't be hard to code up (maybe an edgeBorder property on Rm or something), but I would have figured this functionality was already there.