We are doing a BOM right now that my friends and I agree has horrid directions. Evidently the contract with he LQS states the LQS may not alter the directions! So, I'm cutting the pieces of the block each a hair larger and then trimming them after I assemble each section. Did suggest the LQS give us handouts on 'other ways to make___' in the future [wink, wink.]
Usually pattern makers allow for the seam allowance.
ali