Interesting. Wonder how you would work anti-humor into the muppet formula. He could do a sraight man/funny man routine with Fozzie Bear. Kaufman keeps deliberately messing up the punch-line to Fozzie's set-ups, but Fozzie laughs anyway, 'cuz he's not too bright.
For the finale, something like Cleese's, where he refused to sing any song the band started playing. Kaufman comes on ready to do an Elvis number in full regalia, then when he starts singing, it's the weirdo slavic guy's voice, the band gets confused, and they have to start all over again.
And at the end where they all come on stage and say good-bye, Kaufman could announce that he wants to wrestle Miss Piggy, and then Miss Piggy comes on and knocks him down with one karate chop. (If they can get the sexual innuendo past Lew Grade.)
(Caveat: I only know Kaufman from Taxi and Jim Carrey's portrayal in the Forman film.)