So adding some custom resolutions by EDID to a non Freesync LCD like:
1920x1080 (or whatever native resolution) x59hz
1920x1080x57.4hz
1920x1080x55hz
1920x1080x54hz
1920x1080x53hz
1920x1080x52hz
1920x1080x50hz
This voids warranty, blablabla, etc but works fine on most LCDs, and will get perfect scroll. However the resolution needs to be selected manually, with script,etc. before running Mame, which is a bit shabby.
Many ViewSonic LCD monitors support this without needing to touch the EDID, you can add resolutions even just using the AMD/nVidia control panel and it works.
Then you just have to set up Groovy for using the 'static' method according to your card (amd or nvidia), which is basically the first half of the LCD guide posted on eiusdemmodi.
(of course the ViewSonics are also fully compatible with CRT_Emudriver and therefore dynamic mode. guess it's the right choice for those who actually care about their monitor's warranty.
)
That aside, I've been curious about your method, which I'll certainly try on a variety of non-ViewSonic monitors including laptops (doubt my nVidia Optimus one will do tho, since it's mostly controlled by an Intel iGPU)
Now I'm not sure why you posted about that in this particular thread, is it because you're thinking of combining that software BFI with that alternative varied refreshes method ?
(probably you do yes, sorry for the question it's just that the thought of it is quite the stretch, I mean going from a typical super-limited 60Hz display to a variable, or at least 'multi' refresh rates + BFI with only a software mod, sounds huge)