You are probably aware, but just in case: K (v4) is underlying Q. You can get to it by typing a single backslash followed by enter (or alternatively, prefixing a line with "k)", or loading a script that has the .k extension)

K (v5) is shaping up here http://kparc.com/ . Still early, but it looks like if Arthur Whitney ran the STEPS project, it would be closer to 2,000 lines, than to 20,000 ...