instead of using the stock shader to downsample, try using something like windowed/lanczos or one of the interpolation shaders. that might keep it sharper.
Found another solution, to first upscale the ir and then using the same setup. I dont know older games just works better 
Did some small changes …
Yeah, the older games don’t lose any detail from the blank lines (obviously, since there was never any detail there to begin with), while high-res games lose half their resolution/detail.
I guess this is the opposite to Waifu2x? Haha
lol yeah, Crt0.5x 
If you leave it at full res, some of the CRT shaders can handle the interlacing flickering properly, and crt-guest-dr-venom has some different interlacing modes that look quite nice while still keeping the CRT feel.
