Haha it's actually in the installation instructions that are included with the download! You're right that it's unintuitive, unfortunately I'm bound by the limitations of the program that I used to make the plugin. Please feel free to reach out if any other issues arise!
Ahh my mistake, I was looking at itch for install instructions.
Might be an idea to ammend the line "It says you will receive a "steam key" - but the key is actually to register the plugin when you run it, nothing to do with Steam." to add something about activating the discs separately and set expectations about how regtistering works more clearly as I made my assumption based on this.
Oh no the way you explain that it's not a steam key is fine, I get why itch has it labeled as such, hopefully they add the option for changing it at some point though.
Having worked with it a little more I wanted to let you know this plugin feels like exactly what I'm looking for when I normally load up a soundfont and has the perfect aditional effects that I'd want as default on my instruments. I could probably have a soundfont with equivalent sounds but having a VST that loads up all these samples by default with a nice array of effects and adjustments will probably save me a lot of time so thank you.