Trying to deinterlace with Bob NVEnc; job crashes

[Selur]

QTGMC was used in Draft, since that is the only way I can come close to an acceptable speed of 30 FPS for 1080i25 video files.

LOL, you could have lead with that speed is the main concern.
But I'm a bit confused that you speak of 1080i25 files, since your sample is only SD.

How fast is this for you:

ffmpeg -y -loglevel fatal -noautorotate -nostdin -hwaccel auto -threads 8 -r 25/1 -analyzeduration 5M -probesize 5M -i "G:\TestClips&Co\files\MPEG-4 H.264\1080i_25fps_Panasonic_GH1.MTS" -map 0:0 -an -sn -vf bwdif=mode=1:parity=-1:deint=1,crop=718:1076:2:4,zscale=rangein=tv:range=tv -pix_fmt yuv420p10le -strict -1 -vsync 0 -f yuv4mpegpipe - | NVEncC --y4m -i - --fps 50.000 --codec h265 --profile main10 --level auto --tier high --sar 1:1 --lookahead 32 --output-depth 10 --vbrhq 0 --vbr-quality 23.00 --aq --aq-strength 5 --gop-len 0 --ref 7 --nonrefp --bframes 0 --no-b-adapt --mv-precision Q-pel --preset default --colorrange limited --colorprim undef --colormatrix bt709 --cuda-schedule sync --output "E:\Temp\1080i_25fps_Panasonic_GH1_2021-08-21@22_04_03_3210_01.265"

On my system I get ~100fps with that,...

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Sadly those documentations are not really helpful, then I could probably start reading the ffmpeg source code.