Until the latest firmware for the P1P, when the filament would run out, I would simply use the Load command, the new filament would load and the print would continue.
Today, I experienced something scary. I press the Load button, the new filament was grabbed, purged then instead of continuing the printout, the head ran right through the part that was printing, knocking it out.
I stopped the printer, recalibrated it and no damage was done.
But this was scary!