Interesting that it worked on an A3000 as that has a built in Flicker Fixer / Scan Doubler for use on normal VGA monitors, whereas all the other Amiga's don't (not sure about the A4000)
A4000 doesn't have a built in scandoubler, unfortunately.
Commodore 1942, 1950, and 1960 (I believe) monitors are all multisync and support 15khz modes as well as VGA-type rates.
