Assuming we could make enough space in the NIBL ROM to have the lookup table and the scan code those might be a really interesting way to do it. RETURN as TERM is a good idea but, ESC as ABORT may not be depending on how we map the full ASCII set as we will need two SHIFTS (CTRL and SHIFT maybe) so maybe DEL as being a useful key to stand alone doubles as ABORT.
We need to scribble on a copy of the current grid layout... oh look