The big problem with that would be the center hole on the wheel is bigger than the base on the tire changer. Anything bigger than a 6 lug pickup wheel would be a stretch for this one, to be honest.
/ Portable Mount for the Harbor Freight Portable Tire Changer
Cut a couple discs out of 3/4 plywood as adaptors and large center hole rims can be used. I made a set for my isuzu truck with 19.5 rims with about a 8 inch center hole.
You have to use carriage bolts up thru the plywood to center the wheel and keep it from turning.
/ Portable Mount for the Harbor Freight Portable Tire Changer
One of the problems with the larger tires is that the tires are also tougher to wrestle with, with tougher side walls.. However, tire shops may manually mount and dismount 20" and 22.5" semi-truck tires.
A cheater on the mounting hook is a bad idea.
I welded a longer, heavier duty shaft onto the hook. I had a lot of problems with it twisting. A piece of box tubing on the shaft gives the hook a lot of extra stability from twisting, and also strengthens the shaft somewhat.
I'm also contemplating the square tubing on the other end too help keep it from twisting and gouging the rim.