The 10 out of 11.5 absolutely exists, and is an option in the ANTC rulebook. I've worked at LORTs that use this option as well.
Yes, it sucks for the crew, especially if it's common practice to back their call up so it's a true hour before every actor call. But that's not the practice everywhere.
Personally, I'm a fan of the 10 out of 11.5 if the following are true:
-Preset/crew rally for continuing tech is under ~35 minutes.
-Director, designers, etc. agree to take a walkaway meal break, even if it's only 20-30 minutes to clear their heads and have a sandwich.
-The cast are on board with a shorter day, rather than a longer break. This is only really a factor if they are traveling from a long distance ("Yes, please, let us out in time to get the 11:41pm train!") or have some other personal need for a shorter span of day. The only time I've had an actor approach me requesting the longer break was when they had severe acid reflux that wasn't responding to treatment, and were worried about eating and then singing too soon.