On my current machine, it takes between 3 and 4 minutes to build the documentation. Bean Validation for example takes less than a minute. The key difference is that Bean Validation embarks the DocBook dtd or xsd and locally reference them from the docbook xml files.

Explore how to do that for Hibernate OGM (and Search and Vaidator). I suspect that since the docbook processing is a maven module, we won't be able to easily reuse that. But we could bring the dtd in our git repo and point them locally.