I decided to just start a new thread because I didn't want to hijack someone else's.
Anyway, having scroll bar position properties and events are nice, but I'm thinking this might not be sufficient to do what I was thinking. I had tried to describe this auto-centering in another thread, but it's easier to just show you in a video I made.
Notice that when zoomed in the cursor stays centered in the middle of the screen and the screen simply pans. And that when it gets to the screens edge, the mouse cursor moves. I've used this for a couple years on my iPhone and it's very intuitive. Having to scroll around when zoomed in with ViewerX (and other VNC viewers) is painful in comparison. It may be that some key combination like Ctrl-Alt would be needed to give the cursor back to the system, or if one moves the cursor passed one side of the screen, the cursor would "pop off" of ViewerX. I suppose you'd have to get into it to determine who to best handle it.
It would also be great if there was a more intuitive zoom property in general, such as maybe a percentage. Maybe I don't understand the current zoom options (ScaleNum & ScaleDen) in ViewerX, but the increments seem very large. I could only get it to zoom increments of what seems like 10%. Maybe it'd be nice if there was simply a percentage zoom property.
I know all this would take some work, but I think your remote management software would benefit, and I've never seen a VNC viewer on Windows that was that intuitive. Yours would be the first.