I printed on the 20x24 emaks this weekend and had not problem whatsoever. The paper was very much in the normal range, around 50 secs at f/11. And the prints looks absolutely beautiful! the tones and just great, very rich. The difference was, I used a newer multigrade head that had the option of exposing with unfiltered light.
What I need to figure out now is how to get my old ilford multigrade head to print without any filter and still be timed.