Skyway and Charles,
I'm not trying to argue cause I really do not know...
but... If you were an assembly line worker on the engine line at Windsor, and time was of the essence...
If the Ford training taught you to fold down ALL the tabs, which takes about a minute for all 32 (unless a special tool was provided), my speculation is as soon as the supervisor turned his back, you would do every other one and you wouldn't look like Lucille Ball on the chocolate line!
I just took the exhaust manifolds off my Mar 66 C-code. Everything indicates they have NEVER been off (no wrench marks on the bolts, no gaskets, and 40 years of surface rust). Only one tab at each bolt was bent 90 deg. Every one of the unbent tabs had an EXACT 5 degree "prebend." When I cleaned them with the wire wheel and looked at the unbent ones with a magnifying glass, here's no fretting at the bend line like would be there if they had been "unbent" once.