The hitch is one issue. The belt final drive is something else and it's a really expensive "else". They reduced the width of the belt when using the V-Star 950 engine in the Bolt/SCR. The weight difference is only 66 pounds, so I'm guessing it was a space issue vs. all-out strength needed. However, pulling a trailer places a greater load on the whole driveline. If the belt can take it, okay. I just wouldn't want to find out the hard way and have one break. Replacement would be involved and expensive. That would not be something I'd want to experience while on a trip. The belt alone is about $340. The pulleys are $177/$530(!)
A chain conversion seems to common among customized Bolts. So, that's doable for strength and gearing changes, at least. Having over a grand in pulleys and a belt sitting on a shelf afterward would be painful! =)