Almost nothing in a shell is discoverable. Are these discoverable? ls, cat, $?, $@, <, >, >>, $(cmd), ${foo}, $((2+2))

If you can take the time to learn these (if not, why are you using a terminal?), then you can learn some shortcuts without them being "discoverable".

An oddball custom Terminal is not discoverable either.

There's no substitute for learning the tools.

If you ever find yourself thinking "weird that there's no way to X", in a shell or editor, you're probably wrong.

And this app is more discoverable? Those shortcuts also work in any text field in MacOS, they aren't proprietary to just a terminal.