Russ, I have the flickerFixer on my A2000 with a Mitsubishi multi-sync
monitor. I have a 25-pin switch box to switch between the Amiga's
interlaced display and the fF display.
This works great! You would do the exact same thing to switch between a
VGA board and the Amiga's RGB portthe only thing you might have to do is
center the picture using the controls on the monitor while looking at the
VGA video. Once this is centered switch to the Amiga's video and center
the picture via preferences. The reason for this is that each video board
will try to center the picture in a different place.
The switch box will be exactly what you want.
– Steve Hall –