I dont have an attachment, but I do have an xt2 (w/Yamaha) and a 3x snowblower (420cc/26in.)
First thing I would do is unbolt the hydrostat "rear end" and dump the fluid. Replace it with a high quality synthetic. With heavy snow and some grip you'll work the xt2 more than the belly mower ever would.
Google "fluid change Tuff Torq K46". I've never had issues but when i got my xt2 the internet convinced me that the OE fluid needed to be upgraded.
Regarding pins, someone pointed out last year, and i completely agree, the pins arent the weak point, its the slop in the pins that cause a failure from time to time. For reference, I replace about 2 pins a year. It's has almost always been my fault (newspapers...)
I really like the 3x system. As advertised, and without a doubt, it pumps more volume than a 2 stage. I clear my driveway on the highest speed most of the time.