The flicker in (2) only affects a small number of pixels, but it happens at edges where the filters take effect. The pixels look like they are blinking between neighboring values at a high rate. I suspect it has to do with how the image is sampled by the TVP from frame to frame and the scaling filter amplifies the differences. Changing the sampling phase and LPF helps a little but really just moves where the problem pixels are at. It’s not a problem when things are moving. Pause screens and menus with non-black backgrounds are where it’s most noticeable. The lq filter uses averages rather than direct copy of pixels and it’s less noticeable with it than with scale. Maybe a (user-controlled) weighted interpolation to control filter strength is a good way to work around the problem.
I’ll post a video when I get home tonight.