The only comment that I would add to this is that I noticed that Brian had identified the drawings of this frame to be suitable for ULF. I don't believe that will work. At least the results will not be as sharp as possible. Normally in ULF work a vacuum frame is used.
The reason that I know this is that I went through all of the questioning and searching awhile back for my own purposes. Jorge, Sandy, and others all related that for the large negatives and good results a vacuum frame was required. I trusted their judgement in this matter.
I would not try to contact print 8X10 prints with just a sheet of glass placed on the negative and paper. The contact between negative and paper would not be good enough to achieve maximum sharpness. I sometimes use a sheet of glass on 4X6 for masks and the results can be unsharp (unintentionally) when I do it this way.
I do use a conventional spring back frame when I have a limited number of 8X10 prints to do.