Here's the experiment to do.
Take two pieces of steak of equal dimensions. Do not pan sear first
Weigh before and after cooking with steam vs no steam to determine moisture loss.
Test time to MR by checking temp q 5'
Cut in half after cooking to see the profile of the cooked meat.
What temp? I'd say 325 with no convection.
My prediction...less weight loss in steam...quicker to temp in steam...perhaps more overcooked meat near the surface with steam...and given the lowish temp better browning with non-steam.