I'm not sure, belt drives take up a lot of width.
But the easy way to find out for sure is to ask whoever makes the unit your looking at.
I would be very surprised if they couldn't tell you up front if they will or not and in many cases they will be able to show you pics of customers bikes with their product on it.
Depends on the width of the belt and if you mind using spacers to move the floorboards out a bit. I run boards off a '10 Bones with my 2" PM belt drive without any spacers. A 3" belt might be running it a little tight on clearance.
I've seen plenty of people run a 2" open belt drive with boards. However, with a 3" belt, you'd need the boards extended for sure. Even then you may be pushing the limits.
This is on my "must have" list. Just saving dough. I can't wait!
I may just go with 2" belt. I really like the floorboards and would hate to lose them. I looked at pm's website and I do not know if there's will work on a 2010 fat boy lo.
Let me get you a BDL at a great price. Another thought is to run Harley Goodies extensions to move your boards out if they are in the way. They move them out 1.25".
I'm skeptical...do you have pictures? Or any sort of evidence? From what I've been told, the boards would need to be extended out to accommodate a 3" belt drive.