Yikes! Figured out where I went wrong. I've been thinking in my head that since my grid is 5x6, I needed 30 L1 blocks and was making 32 because I like to have a couple extras to play with. But I actually only needed 24 because the row starts with a solid square.
That explains why I don't have enough yardage... I was correct with my initial math, just confused in my cutting. Too bad everything is cut now, but I'll probably just piece the triangles out of the unused blocks. Life throws us curves, I try to throw them back harder
