Not to nitpick, but do you have any data on the weight of LVL vs. Trex.? It probably doesn't matter 5# one way or the other.
I've installed plenty of Trex and LVL's in my carpentry career. They are both heavy. If weight is a concern there are parallams that are plywood based, instead of OSB like LVL. The main reason I chose LVL is for the thicker material, up to 1 3/4". When used as a jack platform, it's a solid, non-flexible base too.
Gee, I feel like we should be in the military with all the acronyms.