While playing with your feature i noticed that the export to the LyX
1.6 fileformat via lyx2lyx is not working. I now fixed the bug that
the LyX 1.6.x files were not compilable. But there are still some issues:
Take your example file and export it to LyX 1.6.x format. Then open
this with LyX 1.6.7 and you can see that the PDF output is completely
different from that in LyX 2.0. can you please have a look?
What is the difference between the LaTeX that is output? The only thing
the lyx2lyx does is add \usepackage{feyn} to the preamble. The commands
OUGHT to be the same.
Richard