IIRC Kevin said that Valve have told Pimax that there is no need to update as the tracking is just as good on whatever firmware version, and there is no way for us to easily update.
The reason I ask is that I am talking to them about exchanging / returning an index controller and one of the trouble shooting steps they have for me is
It appears that your base stations require a firmware update. To get your machine into the best state possible, please install any available updates for your devices. Since you’re using a Pimax headset, base station updates and power management features are handled via the Pimax software instead of SteamVR.
so I want to make sure I am correct before I reply saying I cannot do this.