I use a similar technique for typing all the symbols. If I press f I get f, r gives me r, but if I press f and r at the same time with my left index finger positioned between the two keys I get $. w and s are {, e and d are }.

All the other symbols, parens, etc. are mapped to similar one-finger-two-key shortcuts.

Significantly cut down on finger stretching which used to cause me mild pain.