Hmm . . . I’m going to set up Octoprint or perhaps Repetier once the Blackberry Pi arrives. I’ve been using Pronterface so far, and, had I realized I could do what you suggest I might have tried it - but I didn’t know you could enter commands externally while something is printing. It would have been better than losing that huge print. As it is, it gives me something to practice my painting technique in preparation for the final successful pieces.
On a semi-unrelated note, I’ve also lost some prints to thermal runaway errors (It seems to me the thermistors are finicky). This always requires shutting off the printer, and the print is lost. If I “Enable Power Loss Recovery” in the firmware will that save the print data in such a situation?