Thanks for confirming the $15 fee was optional. When you think about it, there should never have been any fee at all. Summiting from the west has always been free. Likewise exiting Trail Crest should also be free and no quota, just like any other hiker starting from outside Inyo. So the $15 fee was a mistake all along as I see it.
But whatever money Inyo was getting by mistake, its over. And now PCT hikers are the only people who can't exit over Trail Crest after starting from outside Inyo NF. Not many did that anyway, but no more.