It's a fact about the inaccuracy. There are actually two problems with the Mini. The first is caused by the owner when they change out the stock. The mistake is made by tightening the four 10-32 gas cylinder screws too much. Ten inch groups at fifty yards are common.
The second is when the barrel heats up. There really isn't anything that can be done about that except to keep all of your shooting down to five rounds at a time. After market barrels can be bought but after the receiver and gas cylinder is mated, the combined price is about the same as an Bushmaster AR.