Sam2 -“Rav Moshe still only meant it as a Chumra, I think. He couched it in very, very strong terms because of the potential abuses he mentined, but Rav Moshe knew that he did not have the power to create a real Issur D’Rabannan. It can only be a Chumra.”
Sorry perhaps you should reread it. He says it’s definitely Ossur. He just said they would specifically Assur this if they were around just like they Assured Ameira L’acum. But he says this alone is Ossur right now because it falls under Zizul Shabbos. So don’t confuse that he is making a new Issur D’rabbonon -he knows he can’t do that. He holds it’s Ossur right now! So if you want to use time clocks -you have to be Somieach on the Debrecener or s/o similar!