I have mounted fiber prints up to 11x11 with a household iron, but "tedious" is too kind a word to describe it. Now that I do mostly matte/semi-matte prints I lightly dampen the backs, interleave with good sturdy paper towels then place that sandwich between sheets of birch plywood and weight the the stack for a day. For me that results in relatively flat prints. I then hinge mount them behind a mat with the window slightly smaller than the image. With a backing board and some acid-free board between it and the print, the whole package makes a sandwich that can stored in clear bags and displayed unframed (if maybe a bit distorted!)

When doing bevel cuts, the trick with the Dexter cutter is to cut from the front surface, and to withdraw the cutter a short distance (about 1/32 or so) from the straightedge when starting the point. Then as the point sinks in, the angle snugs the cutter against the straight edge. It takes a little experimentation to see what works for you.

Some years ago I attended a class by a former curator of a major (non-photo) print collection. He claimed that behind the scenes at major museums like the Philadelphia Art Museum we would see T-squares and Dexter cutters! He also recommended cutting from the front, which I believe others do not, the reason being you can see the exact intersection of the cuts on what will be the visible surface. If using some sort of embossed or foil covered (!!!) mat, the front surface can be protected from the sliding cutter by laying a strip of Bristol board or heavy vellum over it.

I suspect the above techniques may be viewed with some controversy, but they do appear to work if one is meticulous in the operations. It would probably be easier for someone who practiced cutting ten mats a day than ten mats a year. :P