A "few" points… (you really made me put my thinking cap on...)
Yes, I can see the non-readily apparent nature of having a left-turn lane with pavement markings and a regulatory sign restricting left-turns during certain times of day. Typically, the time of day left-turn restrictions were designed for roadways with only one lane in each direction. This was to prevent yielding left-turning motorists from queuing up and obstructing an intersection. The CA MUTCD does not explicitly address roadways with left-turn lanes. However, I believe a time of day turning restriction with a marked left-turn lane is in compliance with the CVC.
It is a popular misconception that the presence of pavement markings mean that once you enter a lane, you’re locked in/committed to completing the indicated turning movement at the intersection. A marked turn lane only delineates where the indicated turning movement may be legally started and is required once you enter an intersection. However, a turning movement may only be started when it is legal to complete it and the posted time of day regulatory signs restricting left-turns prevent motorists from doing so.
A left-turn pavement marking does not regulate the movements within an approach lane prior to entering an intersection (by definition of an intersection, the approach lanes are not considered a part of the intersection). Since the pavement marking simply regulates the turning movement that is required once a motorist legally enters an intersection from that marked lane, the motorist is not in conflict with an official traffic control device (the pavement marking) when the motorist merges out of the marked left-turn lane prior to entering the intersection (provided there is not a set of double solid white lines, island, or median).
I hope that’s clear enough… I think in essence, the left-turn pavement markings and regulatory signs only regulate the turning movement within an intersection. The approach lanes prior to the limit line/crosswalk are not considered part of an intersection per the CVC. Thus, you are not in conflict with any traffic control devices when you merge out of a left-turn lane with a single solid white line prior to entering the intersection.
Also, when I mentioned about the CHP officers not ticketing, I meant it for motorists who had not yet entered the intersection and were attempting to merge back into the through traffic. If you entered the intersection from the left-turn lane, you’ve already clearly broken the law. Also, if you were sitting there waiting to complete your left-turn (i.e. not attempting to merge back into through traffic), I can see you getting a ticket as well.
Again, I hope all that made sense...