Oh, I thought it was to allow fine adjustment of the speed. It's been a while since I've owned one. The Scoutmaster pulley is tapered for that purpose. I suppose it should work then. I've seen some other tables do that although I'm not sure what the expected benefits are.
What the heck, it's not like it's a bad idea to have a spare belt around so you might as well try it and see what it does. Good luck