It seems to me that Mathcad could handle this if it treated pages as real pages. I have often wished for this for the same reason as stated. Then I could decide to display pages side-by-side as do some other products (word processors, for example). I imagine that many of us are running wider displays these days.
OTOH, most of the time I use the single print page feature (my default, in fact) and place all sorts of material, from notes to calcs, to the right of the printed page. I count on those areas not printing AND I count on the Mathcad calc order working the way it does when I put calcs there. I could as well put the calcs in areas that I hide at printing time, and that could apply to notes as well. It would extend the document during development and potentially require formatting attention at print time, but that solution might work if Mathcad worked with real pages, because the hidden areas would then be only a page wide and would not affect pages to the right.
Don't know if it is possible to have the best of both worlds. If the page display is single column, permit the non-printing area to be displayed, and if pages are displayed side-by-side, hide the non-printing area? I guess the solution above is cleaner with real page boundaries...
Just some alternative thoughts dashed off...
Rich
http://www.downeastengineering.com/