The mac refresh rate is different fomr what a PC or PC-standard VGA device will output. Until the advent of "multisync" displays all the mac monitors supported Apple's refresh rates exclusively. By the mid to late 90's Apple did away with that because it was getting obvious that 60hz+ refresh rates were the preferred standard and the vendors were gatting annoyed programming the weird rates Apple was using.

The dip switch adapter only toggle bits on the monitor ID pins for the mac. They set the max supported screen resolutions for the Monitors control panel.

That being said, if you have access to a multisunc Sony monitor, use that. Trinitron tubes were and still are the best CRT tubes you can get.