Declarative configuration fixes this problem. You don’t really have to write down how to setup something because the configuration is the description.
I use NixOS so in my case all the stuff you described would be defined in a Nix code in a separate Calibre module. I can enable and disable such module at will with a single option in my main config file.
I really recommend looking into immutable, declarative systems. I think NixOS is the most complete solution but there are some other too. I have no experience with them though.
Sure, Proton Mail is great - I’m using it too. I don’t need Unlimited for this though, just Mail Plus.