CRT and VGA displays simultaneously on stock A1200?

[SACC-guy]

IMO..
Best solution! find a monitor that responses to both 15 and 31 modes. (multi-sync)

I use a Dell SR2320lf that does this and do not plug/unplug. there are others..

The other solution You already have is a dual monitor, but better is rgb and indivision vga setup.

[SACC-guy]

I too have an Indivision ECS, and can see both screens, because my Dell monitor is picking up the 15 mode.

I just helped another use setup a 4000 with a RTG card and we discovered in a dual monitor system, it's software (cybergraphics)
turned off the rgb when the VGA was running