Ionic,
Funny you should ask this question just now, as I was about to post my latest creation. I previously owned a 445 with the PowerFlow system and the MC519 Material Collection dump cart. I loved the way it worked, and made Fall leaves effortless.
Fast forward. Moved. Bigger house. Bigger lot. Need bigger tractor. Upgraded to 2210 after a year of research. I really struggled between the X-series that can use the collection system, the 2210 with the new X-series deck, but no collection system and a 4110 with the old deck. Betting on the fact I could make it work, I bought the 2210 with the 62 MMM and the Powerflow head and MC519 spec-ed for an X-series.
Just this fall I designed and welded up a bolt on hitch that makes the MC519 cart I-match and 3pt compatible. Works just as great as it did on the 445, but now I can lift it 3ft in the air and dump on previous piles of clippings. You could not do this with the normal setup. I generally end up carrying the cart about 6 inches off the ground while mowing. The 2210 doesn稚 mind, and its not as hard on the cart. It does go up and down with the MMM, but that has not been an issue. I plan on designing an independent hydraulic cylinder to replace the push rod off the left 3pt lift arm which lifts the MMM. I would use one of the circuits off the loader control to lift the MMM, and the 3pt would be independent.
Anyhow, check out the photos and let me know what you think. Maybe for the right price, I could make you one too. I have been using it only with the 3pt links and not the I-match as it pushes the cart back another 4 and the chute is a little short, falling off when dumping. Genuine JD parts and no- clog performance, plus no bags to dump!