Learning generally boils down to "Repetition or the avoidance of pain", some people learn by doing, some by watching and some just have to pee on the electric fence.
Whether you think that you can, or that you can't, you are usually right. Henry Ford
Interesting plan, I have not done this but myself but I think I would lower the FB about 4" and slope the top to the original location, make an adjustable damper for the throat at about 125% the norm wide open. This should allow you to get the high temperature and draft with the smallest fire in the FB.
Making memories!
Current Smokers: Backyard RF Offset and Hybrid RF Offset trailer rig with Cowboy cooker and fish fryer, always room for more........
Rodcrafter has you covered !!! The increased air movement and damper will allow great control and max heat from fire ! Im gonna go out on a limb and say if he built a small offset it would still be HEAVY[emoji12]