In the Bluray of one of my favourite movies, the picture (23,976fps) is much better than on the DVD (25fps). Unfortunately, the new sound is bad compared to the DVD.

So I would like to merge the old sound with the new video. Target is an MKV container that should play on a Philips OLED.
1) Should I target the original 24fps of the movie or stick to the 23,976fps of the Bluray? The latter seems easier if there is no downside.
2) I found this thread to go from 23,976 to 24. Can any of the Swiss Army Knife tools (staxrip, handbrake, ...) do this easily? What would the vapoursynth filters equivalent to AssumeFPS and BlendFPS be nowadays?
3) Would you recommend to use the avisynth/vapoursynth filters to go from the 25fps audio to the 23,976/24fps video or is there a better audio-only tool for this purpose? There is no height adjustment necessary as this process would just revert screwing the original audio, correct?

Best regards