Competition use chain guide for competitive riders, used in the E-Xplorer event to stop chain de-railing and rear sprockets from bending.
This in house EBMX design has a slider mechanism to work with 46T-53T rear sprockets, it's strong enough to do the job but also designed to bend out of the way and not crack the aluminium standoffs in a large impact event.
Once you've committed to an upgraded controller, motor and battery the existing design pulls and stretches the chain to the point of component failure, even a 520 chain was not designed for the electric torque these bikes can produce. If you're pushing it on the track or just an aggressive rider running a fully upgraded bike, a chain guide is a must to save your rear sprocket and to stop losing your chain on impact landings.