My only guess is that from a time/cost/payback perspective, it comes out better to just have the extensions fabricated.
he's trying his best for the expense to be as low as possible for buyers, and mentioned a few times he's barely breaking even on his time spent on working already.
You have to consider that modifying the A-arms requires him to buy the arm and do all that work himself (that's expense + time), vs having a machine shop make a small bulk order of the extensions. I'm not sure where one guy would even find so many A-arms - how many SAS leftovers can be in one place, lol?
That's just my guess.
not sure how the welding of the lower bracket is done - once I get mine i'll post up here about it. But gotta wait on some $$ from Uncle Sam first...