PQ Universal is simply a liquid version of ID-62, which is a benzotriazole-spiked phenidone-based version of the original MQ ID-20?
...and Multigrade compared to this does what for the pix? Eliminates toning introduced by the developer?
To me, I find the largest difference to be in the whites. I find PQ a bit punchier there, while MG is better for taming contrast and getting a slightly softer look in the whites.
Perhaps what I am seeing is not a difference in curve shape at all, but just a slight difference in tone? If this was the case, I'd think I would see the opposite, however, with the slightly warmer developer making the highlights look a bit more soft.
Where does Bromophen fit into the picture?