Jed,

No, you are absolutely right! It is I who am taking liberties by referring to these substitutions by the chords I substitute them for.

I also use that A sub in place of either A or when I'm to lazy to reach for the Am9 and I in the lower register.

Another one I like;

Here's the merry-go-round>> Bm-F#(m)-G-Em-A-D.
Here's a cool way off>> 2X233X-22122X-1X011X-01000X-X02030-X00232.

And yet another observation. Sometimes when you have the progression that goes from C-D7-G-C it's a good time to get "dim"-witted and go; 332010-201212-320000-332010.