Connecting a Pi to a Pi?

[GSalvato]

So are you able to use Qt to connect to a target Pi from a dev Pi?

I use a different approach.
I use VNC to connect to the target and develop/debug the software directly on the destination Pi. The OpenGLES Window is not transferred via VNC but is shown only on the monitor connected to the Raspberry. So I have both the graphical window (on the target Raspberry) and the IDE/Debug window in the dev screen.

Simple but effective.