Prime userkeys with embedded escape characters?

[Stevetuc]

There is a very interesting thread in the general forum about setting up HP-71B userkeys with embedded escape characters such as chr$(8) to perform a non-destructive backspace

HP-71B Custom Key Definitions to save lots of keystrokes

I wondered if the same could be achieved on the Prime? It's possible to configure a userkey on the prime to return a string to the command line, but embedded escape characters seem just to print as a rectangle.

HP Prime escape sequences

Code:

KEY K_4()
BEGIN
  RETURN "TEST"+CHAR(8);
 //RETURN "TEST\X08"; //alturnative
END;

There is also a program in the Prime software library called
CSTMENU
This allows user defined softkeys to return a string, but embedded escape sequences have same result as described above.
Any thoughts?