Stutter stoppers are generic, plug into the receiver, use the battery slot. Doesn't need to be made for a specific speed control. Just a capacitor that helps hold the voltage temporarily when ya punch it.

Another option to the receiver battery is an outboard BEC, Castle makes what appears to be a nice one. Wouldn't perform as well as a separate battery, which separates radio and drive completely, but might/should inprove things enough. Advantage is no receiver battery maintenance, install and forget essentially.

Oh, and as I understand it you just pull the red/positive wire only from the speedo plug. Being sure to wrap it up safely.