As long as I aligned cars, and owned my own front end machine, there is no max that I ever heard of.
As I already have posted, MOOG Makes problem solver parts for cars that can't be easily aligned with the stock pieces, such as offset pivot shafts for the upper control arms on GM RWD cars. Not every car is made like all the others that run down the assembly line. You may align 50 cars that come in with minimal adjustments, then you get the one that is an oddball that may give you fits. Sometimes it's due to collision damage, sometimes it just wasn't put together same as it's twins were when new.
FWIW, I've stacked shims on stock cars to get the camber on the RF to at least 2 degrees, then the front end gets pounded hard on a rough dirt track for years, no bad experiences with any of the shims or bolts on any of the cars.
