Few Californians will have any idea why they’re being asked to vote this fall on workplace conditions in the private ambulance industry. But the backstory is a reminder of how ballot measures are the ultimate Plan B for those who don’t get satisfaction from the Legislature. The track record for such efforts is mixed. The key question will probably be whether the proposal’s low profile — so far under the mainstream political radar — makes it seem harmless and easy for voters to support, or too obscure and not worth the risk. Proposition 11 asks voters to give private ambulance companies the power to keep their workers on duty during meal and rest breaks. If a 911 call comes in, those workers could be required to put away their lunch and respond to the emergency.