Not with a PB switch, any Sensor Switch, Gemini II or the Baselog has two separate units all the way through and the batteries will not be affected. But you need to select a unit with a Regulator capacity large enough to deal with the load produced.

Powerbox is a product brand and item name. Powerbox switched regulators and Powerbox units are completely different things.

With both model size and servo load dictates what to use.
Anything 2m and above a full Powerbox is a good way to go, either with serial Rx's or Single PWM Rx's.
Where manufactures only offer Powersafe Rx's and normal voltage servos are use a Switch with regulator is the only choice. Spektrum offer Remotes that allow SRS Powerboxes to be used.