I think it was Geoff, but one of their engineers did a terrific book about his time with the Beatles. Recounted how they came upon all those weird sounds. Said McCartney was a fiend at the boards, and was such a perfectionist that he’d be there long after everyone else left. Drove them crazy.
Norman Smith was their first Engineer thru Rubber Soul.
Geoff Emerick actually did a special remastering of Sgt Pepper for its 30th anniversary...and somehow I have a copy of that unreleased version. Definitely more clear & detailed than the originally mastering.
A Beatles Historian did the best version of documenting their recordings. His last name begins with “M” - can’t recall his name...