I had the same deal with the heater valve control. I modified the wire and I never checked the effective travel - it was closed in one direction, and open in the other and half way in the middle and that made me happy. I sent pictures and explained the situation to the tech support folks and they didn't really seem to care or want to work with me to fix the situation for future buyers.
Have you tried to install the defroster hoses yet???
I started with an original AC firewall with the BIG hole for the blower, so I never got to see how the unit would have fit as intended as I had to make brackets to adapt their stuff to the AC firewall - fortunately somebody here had already done this and provided a template for the conversion.
I also didn't like the idea of just installing the water control valve to the hose and letting it flop around, so I fabbed a bracket to hold the valve
View attachment 1716096418
The bracket holds the valve and the return hose and the AC hoses run under the bracket to hold them on the top of the fenderwell and attaches to two existing holes in the face of the fender well.
View attachment 1716096419