As pointed out the only thing to consider is where welding of moly is concerned is the moly tube HAS to be tig welded in place. You will see a minor weight savings from MS to Moly n a simple cage. It wont be a ton of weight to be sure but some. I also prefer outriggers over plates on the floor

"I am not ashamed to confess I am ignorant of what I do not know."

"It's never wrong to do the right thing"