As it happens, one application I'd like to run remotely will only display in a window that is proportionally shaped AND portrait style.

FBReader, for one, and Frozen Bubbles, for another (IIRC), are apps that provide a portrait mode for viewing the app.

Probably not so many people would find this as useful as I, but would it be possible for VNC viewer to do the same?

(Btw, the app is Microsoft Reader.)