Consider using stainless shim stock to achieve a press fit between the barrel extension and the receiver instead of Loctite 620 or other gap filler. I shim anything that's not a press fit. I used to bed with 620, then shim and bed, but I just shim now. I've rebuilt two uppers with no shim or bed and found about .25 moa improvement with shims on the rebuilds. I don't remember whether I bedded both or just one. I don't think the bedding hurts anything, but I don't think it helps either. If you ever want to rebarrel, you might not get the bedded barrel out.
I'd use the BCM before the Aero.
I'd use the BCM before the Aero.