The first issue was a bug in the code, which has been fixed, see:
As for the second one, I’m not sure what happened, but the guide works even to this day with the newest version of godot, as I’ve had to do it a few days ago.
You need to set the key before you build the release template, then you need to put that same key in Godot’s export window, and making sure you use the template you built, not the official ones.
My question is though, I’m also planning on releasing for steam and it appears I need to compile the steam extension as well. Do I need the encryption for that as well?
Alright, after much trial and error with that method eventually scrapped it and went back to the building it on my machine.
All of this stuff worked fine, my issue was strictly related to compiling the GodotSteam extension to work with it, which I had lumped in together as part of the process. For the windows release template, using MingW actually breaks it so you have to use the Visual Studio Compiler for that part.