Lisa, One can print from XY4 running Boxer, with a few dance steps. First, it is necessary to have the loaded printer file in XY be
POSTGHST.PRN or its equivalent, PostScript producing printer file. Then, run TYF (typing the document to a file); save the file to the Mac desktop (which you have mounted in Boxer to a drive letter (I use d:\ for ~/Desktop)), then run the resultant PostScript (filename.PS) file through preview.app and print the resulting pdf from there.
The whole thing can be mostly automated within XY via the keyboard file; I press ctrl-shift-t, for example, and a .ps file pops onto my desktop a moment later. The details of this could be sent to you separately if you want them. I use Quicksilver, too, so my next step, to avoid going to the mouse, is invoking Quicksilver, bringing the .ps file into its first pane, and then with "open" in the second pane hitting enter. The whole thing takes less than ten seconds from the time I print-to-file in XY to printing the pdf from Preview.
Many of the U2 frames are available; I frequently use SPELL, FISHOUT, REGEDIT, the indispensable IDKEY, HELP, many others. Of course, none of the frames that use MS Windows resources work in Boxer; that's why R. Holmgren's TYP frame is useless for printing from DOSBox or Boxer. FW.