This is very, very good. However, I can only be so enthused about another, yet, very good Cooke III. I still think it's dumb to link the last two movements with two, separate solo bass drum strokes. I don't care if Mahler wrote down 11 solo bass drum strokes, as in Stravinsky's "The Rite of Spring". Some creativity is needed there. Do the first one waaay offstage and loud. Then do the second one onstage and softer. If you don't like that idea, switch 'em around. Mix and match. Don't just sit there and keep walloping the bass drum over and over. Tailor the strokes to match where the music is going to.
Just speaking for myself, I hear the passage in the finale, beginning at 20:20 and going to about 20:45, as being loud - really loud (not soft), as in the Samale/Mazzuca version. That's just me. I've thought that from the very first time I heard the Ormandy recording, back in the mid 1970's.
As for the length of the final note, I don't care so much. The dude is already dead by that point. Sure, a bit longer would have been nicer. I agree that it MUST be longer at the end of M9.
Now here's a crazy idea you really won't like: I would end M10 with a volley of offstage cowbells. Lots of them - located waaay offstage, so that you get a more realistic effect. I'd let 'em tinkle away for a good 10 seconds. I might even discretely pipe them in through the sound system (softly!), so the audience can have the feeling of being enveloped by distant cowbells. Think of the ending of the Ives 4th symphony (it's magical!).