I'm pretty sure that must be a later-generation XConfig. The ones I was working on weren't nearly that friendly. They were more compact, using single lines where you've got stanzas. It was best to use a calculator to figure out the correct numbers, and very easy to get it wrong.
Multisyncs aren't *supposed* to be killable by any input, but obviously your experience disagrees. :-)
What I always lusted over was the early Sony multisyncs. Those were beautiful monitors.