I can't comment on that as I'm using RPi which has different (software only) deinterlacers.
"Bob" may sound cool but actually is a pretty simple / poor deinterlacer (have to use SW bob deinterlace here on RPi4 and deinterlaced SD material looks terrible).
The "yadif" and other deinterlacers (not sure what's actually available on PCs) should work a lot better.
Too bad you use a RPi4
I don't have "yadif".
Deinterlace method: VAAPI BOB, VAAPI Motion adaptive or Off.
Video sclaing: Lanczos3 Optimised, Spline36 optimised, Lanczos 2, Bicubic, Bilinear, nearest neighbour or Auto
No suggestions looking at the options?
Is there also an indication on audio delay through HDMI? The mouths and audio are not an 100% in sync. So by how much should i adjust the audio? I get it depends on the tv / setup. But there probably is a general indication on audio delay when using HDMI, right? I think it is somewhere between 0,1 and 0,250 sec. Maybe i am a bit of a perfectionist, but i just like to have (technical) things as good as possible 99,5% is just not doing it for me :p