I have been playing around with Dan's corrugated board stack drying scheme. It just so happens that it is easy to get sheets of 18"x24" corrugated board where I work, so I'm using those for 16x20s. That puts the long side of the print within a half inch of the edge of the board, but the interfacing overhangs by an inch or two more. I only tried it with one print, but it dried within about a day and a half or so. Not bad. Quite flat with a slight linear curl up at the ends. There is a very small waviness but it's on the short edge of the print which actually gets better coverage by the board. I placed a piece of 3/4 inch ply wood on top as a weight. I did not use any forced air.

Since it seemed to work fairly well, I got a bunch more of the cardboard and will continue to use it. The interfacing is polyester and it's fairly thick (relative to some tissue-thin stuff I saw) and it didn't stick to the print or leave any kind of lint or marks in the emulsion. And it's pretty cheap. I have a mounting press, so I will flatten it in that to see if the slight waviness goes away completely after doing so, but for now it was flat enough to stick in a storage box with other prints (previously flattened with a press).

Up to now, I've just laid prints out to dry on a paper covered table and they invariably curled which I would remedy by pressing them in a dry mount press. I don't mind using the press, but like others have said, the press will sometimes not be able to completely eliminate the warping along the edges that is due to nonuniform shrinkage during the drying process. This exercise with Dan's technique is basically to see I can improve things enough to get rid of that occasional residual warping.

BTW, I use Ilford MGIV FB for these 16x20s. I don't think I've seen this residual warping on FB 8x10s.