Surefire Lockout Feature

A recent exchange regarding unanodized tailend threads, lockout, and Surefire got me thinking.
Lockout is possible even with unanodized threads: just design the tailcap so that either a 1/4 or 1/2 twist of the tailcap (from the fully tightened position) breaks contact between the tailcap spring and the negative end of the cell.
Right? What am I missing here? If this true, it means makers who have had to forgo using anodized threads at the tail end due to legal reasons can still provide the lockout feature. Right? And if so, why aren't they doing it?

The Surefire related part: I used to think Surefire twisties achieved lockout by not allowing the conductive ring at the bottom of the tailcap to touch the end of the tail. Now I'm thinking it has just as much to do with that as unscrewing the tailcap far enough so the spring no longer contacts the cell. I think at least my G2 is like this. When I lock it out, the switch is no longer "pressible," because the cell is not making contact with the spring to bounce back the switch. So back to my point: anodized threads can have nothing to do with the lockout feature of a tailcap, just bring contact between the spring and the cell.
I guess the slight rattling is the tradeoff. I wonder if this was or could have been used to fight SF during the lawsuit.

Another drawback: the shorter spring compression/engagement when the tailcap is fully tightened allows the cell to break contact more easily during impacts. But that's something that can still be fixed: 1 full turn of the tailcap for lockout, instead of 1/4 or 1/2.

There is a big difference between the original tailcap of the G2, and the current one. In the original, there is nothing holding the spring in place, so if one is not careful one can have the spring and dome cap in one's lap when removing the tail cap. In the lock-out version, the spring mechanism is held in place by internal threads inside the cap and a little Locktite. The cap is also several millimeters longer to allow room for the lock out position while still engaging the threads on the body of the light.