I wouldn't leave the print in the drymount press. I tried that for flattening a print and didn't like the surface of the print afterwards (gloss fb). For drymounting I put the print in the press for 2 minutes then remove it and place it under this nice piece of 3/4" polished limestone for a local stone fabricator. Marble or granite would have been fine too. The piece I received was a sink cut out which I got for free and then squared up with a diamond blade on my circular saw. The stone is nice because it really soaks up the heat.
Yeah the steel plate from Seal would be nice too, but not for 259 bucks.