One of the fun things about this hobby is finding better ways to do things. We all start with kits and the usual configuration for a build. Some of us move to "less conventional" approaches to eliminate weak points. Others innovate to enhance safety or speed like adding disc brakes, using BMX chains, and adding geared hubs. One thing is a fact, anything that adds drag to the drive train is going to rob HP from these little engines. If you can do without a tensioner, that's a plus. If you can't, that's ok too. Do what makes for the most fun and celebrate the variety in the sport.