Without knowing the sequence of IO operations you’re using it’s difficult to give a precise answer.
One approach would be to write a record format (perhaps the subfile control record but not the subfile itself) that is not using the OVERLAY keyword. Not having OVERLAY would cause the display image to be tossed. Another would be to rewrite the subfile control record and subfile after using SFLINZ. Or using SFLCLR and writing a ‘end of list’ subfile entry. There are really quite a few ways to get rid of that data — it just depends on what you want to end up with on the display device.