I have had a K2 Plus for about four months, and recently I had the second instance of the nozzle crashing into the plate, scratching it severely, during flow calibration, immediately after leveling. The PEI plate was spotlessly clean and nothing was underneath it.
In both cases, the scratched area was at the top (away from the door) of the pattern on the left side of the plate. The damage to the plate was virtually identical.