Okay so I had a bunch of silly issues going on yesterday that were just building up against me late in the day. My first issue was getting everything to target the x64 bit platform which was an easy setting change in the solution's properties. My next issue was that I was using "btn.ExecuteMethod" in my vbs file that builds the custom menu to launch my custom exes through a script shell. That script shell had no clue about the environment settings, as you correctly pointed out, which is why I was getting that clsid error. I tried the correct solution yesterday but I had bad syntax, so the button I thought I was changing the behavior of...yeah...wasn't that button. Knew I was doing something dumb in there.
Anyway, I changed the behavior of the calling argument for launching my code from btn.ExecuteMethod then doing the wscript shell nonsense to just
btn.OnAction = "run \\some\network\location\viafinder.exe"
and it works! yay!