Yes, I know the K3 and K4 are quite different in many respects.
I was just stating that it "could happen" that the file does not get deleted.
And the user storage feature implementation is very similar among all machines.
An even better question, better suited for a topic of its own, is:
How do you exit diags when ENABLE_DIAGS does not get deleted and the USB port is burned out?
My first guess at that one: Ship it back home.