Hey, Sorry to get back to you late.
Yeah I'm happy to share with you my script, however my script is actually written in vapoursynth, not avisynth. Also, my script is still very unfinished, I am working on improving it, however not only does it have pretty bad performance, but it still isn't perfect. Nonetheless, if you want to try porting it to avisynth feel free, i am sure that the same general idea could be achieved. I also really want to stress that it is super unfinished, it's just the result of me messing around, so not only is the code a bit of a mess, but there are sections that either don't do anything anymore, don't work as intended, etc.
Here's my current script:
https://pastebin.com/XAaAjain
Currently I'm trying to implement pattern detection, I have a few preset patterns that it can detect, and it will choose the best pattern for each scene. However ideally the pattern detection would be dynamic, where the pattern is changed to fit the pattern of the surrounding 20 or so frames. No idea how I would go about that. Currently it is able to detect all 5 TTTBB, and all 5 BBXTT combinations, as I found they were the most common in my source. Where T is Top Field, B is bottom field, and X means that neither field is good, and to repeat the previous good field (which will then be removed in decimation hopefully).
If you have any questions feel free to ask! I'll try to answer them to the best of my ability. The script was working at around 80% accuracy without the pattern detection, so I guess implementing that would still be better than nothing.