For this remapping and a few others I'm using Karabiner for OSX. I remap elisp commands in emacs all the time, but I don't know how to remap the keybinding for the single SHIFT to parens. The answer might be here: https://www.gnu.org/software/emacs/manual/html_node/elisp/Ch...

Karabiner is pretty good though, and you can select certain keybindings to only work in emacs.

I've also remapped CONTROL to CAPS LOCK, a more common re-binding to save one's left-hand from endless torture and mutilation!

Karabiner https://pqrs.org/osx/karabiner/index.html.en On GitHub https://github.com/tekezo/Karabiner

It's also pretty simple to extend Karabiner with XML scripts.