If you want something that looks different you wanna find a different desktop environment(DE), most of them are avalible on most distros. I’d pick a distro then a DE that they offer. You could try these DEs you haven’t already tested:

• Cosmic, think tilling + gnome-like interface. It softens the learning curve for a tilling WM a lot if you’ve got other options. Fedora has a spin with this in if you liked fedora.
• Budgie but can be quite similar to others
• MXLinux with Fluxbox could be an interesting choice, its usually used on low end devices but its pretty snappy on anything else. Or Fluxbox on any other distro but MX is the only thing I can think of with it as an install option.
• If you don’t mind something older, you could look at CDE or NsCDE, although I can’t remember how involved the install process is.

Other than that, your options for non-tranditional desktop environments are probably just other tilling ones(i3, hyprland, ect) or scrolling(like niri). Or customising one of the others, KDE can be very flexible for that. You’ve gone through a lot of the main ones.

As for distros, there’s a lot, most will have the same set of desktop environments though. So, the same look and feel one you get past the install and package management etc…

If you don’t mind going outside linux land, haiku can be fun. Completely different OS though…