Yes on merging with 0.77. I already merged with an old version of 0.77 a while back but never posted it. I just tried to merge with the latest 0.77 changes and diff gave up and just told me the whole scanconverter.v file is different without identifying specific changes. It will be fixed this weekend and a new file will be posted.
l4x and l5x filtering is a lot of work that I don’t have time to look into right now. There’s not much space left on the FPGA without making some of the changes marqs mentioned a while back. I’m not sure whether 4x or 5x filtering is even possible without more room. scale4x is probably scale2x applied twice. Not sure if scale5x is even defined or if I would need to make it up. I took some shortcuts in hq3x to use a lot of the hq2x code (which was already based on code with shortcuts).