I am putting in a stud wall to divide a bedroom up. Problem is when trying to fit noggins to ceiling joists I found that the plaster key (that protrudes above the laths) mean that the noggins will not sit level with the laths. Should I - 1. knock the plaster key off at this point or 2. Let the noggins sit on the plaster key and fix the ceiling plate up to the ceiling as tight as possible?