ModeShape's EAP configuration does not process correctly custom Hibernate Search properties

ModeShape's EAP kit allows custom hibernate search attributes to be passed down via the indexing configuration. For example:

 <indexing 
rebuild-upon-startup="fail_if_missing"
rebuild-upon-startup-include-system-content="true"
rebuild-upon-startup-mode="async" hibernate.search.nodeinfo.indexmanager="near-real-time"/>

However, it seems these are not passed down correctly to the JSON config when the repository is started.