Exactly what I was thinking of with respect to kludges necessary for backwards compatibility. I think Commodore made one monitor that supported a bi-modal scan

Exactly what I was thinking of with respect to kludges necessary for backwards compatibility. I think Commodore made one monitor that supported a bi-modal scan rate, and it was something like twice as expensive as the the regular Amiga monitor range. I also recall a somewhat exotic NEC 17" flat-face CRT monitor that was completely out of the question pricewise for almost anybody except institutions, that also could do it by virtue of having a continuously variable sync clock from 15 khz up to 45 or so.