I'd like to use the DocBook Stylesheets 2.0.3 for generating HTML5.

Will they be included in the next release of oXygen?

Or can I add them myself?

Okay, I can use Saxon-EE for XSD 1.1 validation, but I still do get Xerces validation errors.

Is it possible to replace Oxygen's Xerces version by the current trunk version of Xerces for avoiding the nasty Xerces validation errors for assertion elements?