I texted with the guide I had on my trip last May (2016) - he leads trips there several times a month for a major tour company. He says the lines for the buses on the way up are pretty long all the time now. But as before the rule change, still the best way to avoid long waiting lines for the return buses is to leave late in the afternoon; not more than 15 minutes. Plus, on sunny days, the best light for photos is in the afternoon just before sunset.