How to end loop on laravel excel with OnEachRow concern?

Hi, due to complexity on the excel (withMultipleSheets) I need to import I have to use onEachRow concern, but my problem is that my needed data ends on row 500, and I would like to stop reading there to move into the next sheet. Now i have to wait until the reading of that sheet stops by itself by reaching the highest row.

¿Do you know how can i do this stop reading (sheet) thing or is instead impossible and I have to stick with this aduous (and sometimes infinite) waiting process?