Nice work!

I built up some box beams, 2x4 top/bottom plates spanned by OSB glued and nailed every inch. Supposed to handle a lot of weight as the tension is in the 2x4's and the shear is in the OSB.
My shop rafters were sagging a bit so I spanned those beams across the 24' of wall and sistered them to the rafters lower span after jacking up the rafters back to level. The beams didn't budge a bit. Also made one 30" tall to span the opening over my 16' door to help carry the load.

Amazing what structural designs can accomplish.