I have precut all of my fabric pieces, but there always seems like there's a little excess that needs to be trimmed. And yes I guess I am asking about chain piecing a bunch of units at once. Although, I'm not sure it would work since some of the seams on the units start or end in the middle of the piece.
The pattern is the Christmas Celebration tree skirt from Quiltworx. It's a gorgeous pattern and I'm really pleased with it so far. The tediousness of the process is what's getting to me right now, haha.