Here is an update (short version):
I made several attempts to link individual valves to individual KPL buttons, but none were correct. I found it much easier to created the links for each KPL button using the snapshot method, and then using the Link Manager modify what zones/program are controlled.
I did find it very helpful to put the KPL in a Tabletop Box (SH part 2290BW) while doing the linking and programming. It was a simple matter of plugging in the box into the nearest outlet, either near the EZRain, computer or window. When I’m done the KPL then gets wired into the wall.
The programming with the Link Manager went fairly well. I found that deleting and adding multiple links sometimes locked up the EZRain. I the end I made one change at a time and then re-read the links after each change. I one case I had to re-read twice before the latest addition showed up. The process was slow, but I was able to make all the individual and program links I wanted.