[snip]

Thanks. Because it still written in python you can look inside script and try to understand what kind of deinterlacer it uses by default (or look at gui field where you hopefully can change this)

The default selectingis "Not deinterlace"
If deinterlace, there is a selection between YADIF and FFMPEG deinterlace.

so, if you come up with better deinterlacing filter (from ffmpeg) you probably can communicate this to program author (or I can do, in future where I actually try said program)