Hi. Well, if your seat is installed tightly and your child is under the LATCH weight limit, I'd leave it. But it's true that Britax designed the ClickTights to be installed with seat belts. There's much less fiddling done with the seat belt on installation than there is with the LATCH belt; it's generally easier. The big problem comes on uninstalling the seat. When installed with LATCH, sometimes it can be very difficult to get the LATCH belt loosened. It's almost as if the ClickTight panel "locks" the LATCH belt tension in its adjuster.
Like I said, if you don't need to move your seat, I'd leave it. But the next time you uninstall your carseat, I'd use the seat belt to reinstall it.