it may be possible that it supports 15.75 khz input, but will only line double it up to 31khz. I have read that several of the large monitors do that. When you are looking at the specs they will say "15.75:31khz" instead of "15-31Khz"
So maybe this monitor can take an arcade signal and display it, just not at it's native resoluton.
Still definitely worth getting IMO.