I am aware the B-17 did not originally use counter rotation; however, it is so easy with electric and makes takeoffs much more pleasent. Per Castle Creations it is not necessary disable BECs as they work just fine in parallel. I also have one of E-Flight's Super Airliners with two of E-Flight's 20 amp controllers in parallel; no problems so far. With the Castle speed controllers in parallel it provides up to 12 amps for radio equipments; I like a bit of overkill.