I use Libra Writer and have found pitfalls in moving a odt file to ePub. These are primarily related to removing unnecessary style commands in the ePub text. Bookapy's conversion works pretty well, and perhaps I should use that as a base.
One recent problem i had was with italic text when a sentence or paragraph was intended to be all italic. The result was normal text. However, when it was mixed style then it was as intended. Via an editor easily corrected, but a pain when it is a large document.
Suggestions?