Yeah the lost 20 scene is certainly my favorite scene Ive never watched. Ive read it and it does give the audience great insight into his character and motivation.
But I do agree with you about just cutting and pasting him into TPM wouldn't be sufficient in establishing him as a character.
I got it...turn Dooku into Qui-Gon! A tougher task even, but hey you can't say his character isn't established in the first film. :D
Seriously though, any editor who wants to change the actual characterizations and motivations of them in the PT has their work cut out for them.
Adywan's PT edit will go far beyond anything he's currently doing. They will be about more than fx touchups and fixing inconsistencies.