This was a surprise submission! I started my own version of this a couple of days ago. Neat.
I thought I had tested that Kritter section to death in my last runs, thinking it was faster to land on the second Kritter because you would land earlier afterwards... I was wrong!
I did improve Manic Mincers by three frames. First off, if you jump with Expresso just before you reach top speed, you'll get to full speed quicker, saving 18 subpixels, which is just enough to be a full pixel ahead. Eventually, thanks to this, I could reduce all the lag frames in the end of the level. Though for personal preference, I took an extra lag frame in favor of saving an in game time frame instead.
6-2 was a lazy TAS from me now, as I just wanted to test to see if would be faster or not in the end, it could possibly be improved further. Movie file here:
http://tasvideos.org/userfiles/info/60738160273252196
Will look more closely to the end levels as well.
EDIT: I also got 6-5 four frames faster so far, thanks to getting more speed towards the left before grabbing the DK barrel. I also saved a lag frame by holding Down shortly after Donkey started to fall when Diddy entered the bonus:
http://tasvideos.org/userfiles/info/60738708608140714