My paper is a brand new box of MGWT, the paper is taken from the box, not a safe. PM me your address and I will send you some of the filter material I am using, which is the same stuff in the filters sold by Freestyle and others for these safelights. You can try it out yourself.
And as I said, I get some fogging when the vanes are wide open after three minutes, but closed down, I get much longer times while still bright enough to work easily.
I should note that I am using these Kodak instructions to perform the test.