When I towed with my Commander (I still have the P3 in the Commander for other trailers, but, I tow with a RAM 2500 now and it has a built-in controller), I used a Prodigy P3. IMHO, one of the finest inertia brake controllers on the market. The nice thing about the P3...with it's abundance of adjustments, it will indeed handle a *big* trailer. It will also handle a popup; anything with electric or electric over hydraulics mounted to the trailer frame
It sounds as if your existing Voyager would probably work OK with enough fiddling, but, if it were me, I'd spring for the P3 and be done with it.