The spec refresh rate is coded as a single value in firmware AFAIK (EDID), but what the panel is actually capable of is different and depends on the controller hardware as well as the construction of the actual image-displaying panel. So it's more a matter of "how far can this LCD be over/underclocked before it starts glitching or fails", which is different for each panel. LCD overclocking was a big thing with DIY'ers before native high-refresh rate panels existed/were common, however it's not something that would be a good idea to do in a shipping product since the over/underclocked performance & stability is not guaranteed.Hmm. I've never bought LCD panels B2B in bulk.
Are refresh rates usually hard coded at a single refresh rate, or is there usually a small range.
With even a small range you'd thing you could make things work with multipliers.
Let's say the panel supports 30 to 60 hz. You could make a pretty decent range work by stretching 30-60 natively, and then duynamically skipping every other frame in software for framerates below 30. Thus 29fps would be rendered every other frame at 58 hz, etc. etc. You'd think this would be able to be done in firmware.