You know, I have 27VRL as well, and was just looking at those mounts yesterday scratching my head.
They are welded securely to the frame. So, in theory, you could probably fab up a bike rack or something to make use of those mounts.
As for rocking. I put the strong arm bars on both front and rear power stabs. Made a world of difference. Coupled with X wheel locks and a couple scissor jacks mid frame we get no bounce or rocking.
2013 Ram 1500 Laramie 5.7
2015 Flagstaff 27VRL