My engineer specified a 5-1/2 x 7-1/4 Microlam beam supported by Simpson WNP608 joist hangers. All the suppliers I've checked say Microlam only comes in 1-3/4" thickness so we would sister 3 pieces. That makes 5-1/4" x 7-1/4". I thought the engineer made a typo but then there is the hanger. It's pocket is 5-1/2" wide. Neither Simpson or USP seem to make a 5-1/4" hanger. I would think the hanger makers and engineered lumber people would be in sync on this. What am I missing?