I'm attempting to mass delete a few statistical JE's via a search with in-line edit, is there a limitation on the number of records I may delete with this technique? (Click + Shift last record)

I've only been limited by my patience and the list length. You can have multiple browser windows. (Or have a simple Mss Update delete script.)

It doesn't usually work for me past 500 lines.

other option is to use mass update script to delete sample https://netsuite.custhelp.com/app/answers/detail/a_id/40768