An interesting UI paradigm I've run across [0] is using a keyboard-accessible hierarchical menu for all actions. It's similar to how AutoCAD works, but the "commands" you type are actually just sequences of menu hints. Most desktop apps support these hints with Alt, so the capability is there, but there is something about using the hint sequences as primary keyboard shortcuts that appeals to me.

The nice thing is that by using the keyboard to navigate menus, you develop muscle memory for "shortcuts" without really trying. And if you ever get "stuck", not knowing how to complete the sequence, you only have to look at the currently open menu.

Formica doesn't do this, but this could be extended into rudimentary scripting.

This kind of paradigm won't fit all software, for example I don't think it's a good fit for software where typing mildly structured text is the main mode of interaction. It might be mainly useful for shortcut-heavy software.

[0]: The software in question: https://www.formica.cz/