As reported by RW:
Loaded up a large document and started to edit in as a test.
Got some error messages that I do not get in DITA.
It makes your source files unusable outside FontoXML so make sure that you have a backup while testing.
I could not figure out how to publish the PDF so I am not sure how the Table of Contents and all of the variable substitutions work.
Overall it looks very good and easy to use.
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