In further versions, additional attributes should be marked with a special style instead of ‘Header 1’. The particular style name will be described in the manual.
This will correct the current behavior of the plug-in, which by default processes additional attributes and unexpected content truncation occurs if the document contains several “Header 1” header blocks.
To convert documents into a new format, you just need to change the style of the additional headers attributes from “Header 1” to a special.
Sorry for any inconvenience.