They say it’s a pour plan! A new law would force Big Apple businesses to let customers use their own cups when ordering a beverage —  but workers tasked with turning away massive bucket-sized mugs aren’t toasting the idea. “I don’t get paid enough to fight with them,” one employee of a Midtown coffee shop, who asked not to be named, said Wednesday. “It could become a problem.” The worker, however, said it was ultimately worth the hassle to help stop single use plastics from ending up in oceans