Erasing the lines

[emaxos]

I understand the emphasis and penalties for deliberately erasing the lines from previous discussions here but saw a sit the other day that raised a question.
I announce HS games from a press box above home plate so I have a great view.
Between innings, umps are chatting about whatever along the first base line. Defense takes the field and before any warmup pitches are thrown, the catcher takes a few swipes at the catcher's box lines. The PU seems to notice this but continues his between innings chat as the pitcher starts throwing her warmups. I know he is aware of the emphasis because he earlier called a strike on a batter for erasing the front line of the batter's box. Following normal pitcher warmups, batter steps in and the inning starts as usual.
Should there be a call in this case and how might that be handled?