Conversion Kits from Prius to Plug-in Prius

Since hymotion stopped doing kits and the PiP came out, there seems to be two companies still offering a conversion kit.
My biggest concern is running the electric motor at highway speeds and whether or not the wiring is capable of handling high currents.

Has anyone installed one of these from Plug-in Supply? If I read it correctly, it sounds like they've only sold a couple hundred.

Plug-In Conversion Kits for Prius, Escape, Highlander, Camry | Plug-In Supply

I do wish Toyota would have given us a second higher capacity battery as an option.