If you don't have the issue, then don't bother, just another thing to add some drag to the drivetrain.
Usually, if belts are flipping, you don't have enough tension in the first place.
I haven't seen one in use since the T2 007, sounds like Chris is the exception.
Xray T4'16, T4'14 (Wet Car)
Xray X12 2016
wlrc.co.uk (West London Racing Centre)