That's pretty much it, right? ZorinOS Pro gives you some more desktop layouts, more wallpapers, and what they call "Zorin Installation Support service". Basically like buying a hat in a free game.

But the "Advanced productivity tools" one is a bit misleading, apparently it's stuff anyone can install from the store it just pre-installs some unnamed apps for you.

I don't mind selling some cosmetic stuff to fund development, the app thing is a bit shady though.

The way I was specifically talking about was for the project to be fully open source, but with an optional paid service aimed at businesses that ensures priority attention to bugs and feature requests. I’ve also seen open source projects with paid binaries, most commonly for iOS where it costs the devs money to keep an app on the app store so users can compile it themselves for free or pay for the (still open source) precompiled app. Open source and paid don’t have to be mutually exclusive, although the culture of free like freedom and free like free beer is great and I hope we never lose that.