Digging into this a little more, I fear it may be a bit more complicated. While Generac Generators are two start capable they do not all have this built-in and you need to buy a 2 wire start Kit for $30 or so. It is basically a bunch of wires that need to be installed as per this document https://rexel-cdn.com/products/66.pdf?i=3DE90BD8-3F92-4C63-A833-FEDC1C27B8F7 My assumption is that Generac do not like people using these generators as true off the grid generators, the 2 wire remote start is somewhat hidden....
I Ended up Buying a Kohler 10RWRes Generator. Installed today. That has inputs for 2 wire start on the board, super straightforward., no contactor or whatnot needed. Its $1300 more expensive but I am impressed with the build quality. (just based on opening it up and installing it). Its is HEAVY though. 428 lb! (vs 260 of the Generac). So Per weight it is the same price as the Generac.