I've got a couple of 60Hz VGA limited LCDs to play around with if I get the chance. One of my "Liberty" adapters is DA-15 to DA-15 and I'm wondering if that might be an example of the Vampire Video Adapters mentioned as compatibility requirement for Apple MultiSyncs in the gamba2 chart?

Not all MultiSync Displays are flexible enough to handle all Mac & NuBus resolution/freq combos. I have a 21" MAG CRT for testing that is simply awesome for testing purposes. It has Mac/DA-15, VGA/HD-15 and 5-BNC inputs with LED readout panel indication of VGA/Mac (likely more) signal, res & freq for whatever is active. But even with that, I've seen "out of Sync" indication on the panel for oddball Mac resolution/freq inputs that don't phase the 17" Sony Trinitron MultiSync in the least. Very strange stuff, Display Juju.