While rates with 30% or greater discounts are not supposed to get points, they can from time to time.
however, as already stated, the 2-4-1 deal is full rate for first night (which should always qualify for points and night credit) and second free night (which may or may not depending on the luck of the draw
I have usually had to request points for the few times I have taken advantage of the 2-4-1 deal, but always get at least the points and credit for first night, sometimes for both.
I am using 2-4-1 for a London stay during April for a conference, where the rates are very high. I am already unhappy with the hotel, as I have been charged for the first night already, but my account now shows the full rate for both the first and second night of my stay, while my e-mail confirmation shows £0 for the second night. I will post my experience in this regard.