Not really needed. But there are options that cost upwards $100+ from Scorched RC and PPS
I’ve yet to use the Scorched but hear good things, and PPS is a really nice upgrade if you really require precision gear mesh and more teeth count options.
I'm a fan of the PPS mount: the micro gear mesh adjustment is fantastic. I have one in my Kraton 6s. The roll cage isn't installed in this pic, but the PPS mount can accommodate one.