[popcornmix]

Where can I set this up exactly so these settings can bet set as default?

running the qpu/advanced deinterlacer

Play a video. Bring up video OSD settings. Make sure "Deinterlace video" is set to "Auto" and "Deinterlace method" is set to "MMAL - Advanced".
Now choose "Set as default for all videos" and you should find any interlaced video you play uses the high quality algorithm.

I recommend adding

Code:

gpu_freq=400
force_turbo=1

which doesn't set your warranty bit (assuming you don't specify over_voltage) and seems to work on most Pi's.
You may be able to set gpu_freq=500 which gives a bit more overhead (e.g. when there are overlays on screen).