As title says. Obviously I could setup different virtual machines or spend the time and install all the DEs in one VM if it is even possible without breaking the OS. I'm wondering if there is an already made iso or something that installs all the maintained DEs for trying.
All modern distros let you install them all and just select which one you wish to use from the login screen. You don't need NixOS or anything specifically to do this, in fact it's easier on other distros because usually nothing more than installing the packages is required, no config editing, rebuilding or even rebooting.