And things turn really "fun" when you begin using modifiers which aren't supported by the USB keyboards specs, like the Hyper key. I've got my Linux / X configured to use Super and Hyper keys but things quickly turn weird. For example the Hyper key works totally fine from Emacs in GUI mode (and, over the years, I assigned a huge number of shortcuts to the Hyper key), since years and years, but I have never spent the time to make it work in the terminal. It's doable but requires some arcane magic. I'm not even talking about having the Hyper key working from a tty (like if I boot in non graphical mode) but simply having it work from, say, an xterm under X. Oh the fun.
So until I fix that no "emacs -nw" (emacs in terminal mode) for me as I rely way too much on my Hyper key.
You dont need to do anything fun. Just convince emacs developers to support a modern terminal keyboard protocol. https://sw.kovidgoyal.net/kitty/keyboard-protocol/ and you get support for hyper out of the box.
It's more than just the Hyper key (as I'm sure you're aware). The article mentions how C-S-anything is the same as C-anything. I've always wanted to set up a fully functional terminal Emacs (for playing through ssh on a tethered connection in a café) but it seems to be a fairly in-depth process to have an interface with all the things. I use QMK extensively in tandem with my Emacs configuration, and there is a ton of functionality to transpose to the terminal. Ultimately I think I would have to completely redo my configuration in both QMK/KMonad and Emacs to stick to the codes that are sent correctly.
Sending "F18 a" with QMK or KMonad (a random prefix-combo I picked for example purposes) instead of "H-whatever" (for whatever keystroke combo you have H-whatever bound) would work with a terminal in your case, but you'd have to change all those bindings and setup QMK/KMonad accordingly. That's altogether too much work.
Another fun modifier is the Office key, which actually sends Ctrl+Alt+Shift+Win, so if you can manage to hold down all the keys Ctrl+Alt+Shift+Win+L will open LinkedIn on Windows laptops.
So until I fix that no "emacs -nw" (emacs in terminal mode) for me as I rely way too much on my Hyper key.