vim-arpeggio

Die hard vimeleon here. IMHO chording the 'j' and 'k' keys simultaneously [1] is a severely underutilized solution for escape. Try it. You'll love it. If you're going to rebind capslock to something — and this is particularly true if you're on macOS — rebind it to backspace. Capslock escape isn't useful outside of Vim. Backspace is useful everywhere, including inside Vim. [1] https://github.com/kana/vim-arpeggio

There's also vim-arpeggio, with which you can define mappings for simultanously held-down keys: https://github.com/kana/vim-arpeggio

Vim already has the capability to allow pressing a key chord to perform a custom function. Just use the plugin vim-arpeggio at https://github.com/kana/vim-arpeggio. And you can already do something like “DFD” expanding to “def someFunction(arg): stuff” by using the vim-snipmate plugin at https://github.com/garbas/vim-snipmate. That “snippets” functionality is based on TextMate’s snippets feature, and I know Eclipse supports snippets too. Thus, steno is not necessary for either of the advantages mentioned. However, it still might be good to have the mindset of using tools like vim-arpeggio more, and steno still might make typing variable names slightly faster.