It could be very practical if KHelpCentre (KHC) also supported compiled Qt help documents (.qch) or better yet, collections of such documentation. This would make it a prime candidate for use as an external documentation browser for KDE's own IDE, KDevelop. It already uses KHC for its own handbook; with .qch support KHC could be used as a browser for 2 of the 3 standard documentation plugins that come with KDevelop (I'm currently working on an external viewer mod for just the QtHelp plugin that uses Qt's Assistant). Support for user-defined collections would be important here, for 2 main reasons: - developer documentation is developer-specific, may vary over time and can be installed in multiple locations, making a simple fixed/hardcoded repository location inpractical. - on Mac, there's a bug somewhere in the QtHelp implementation or its underlying APIs which limits the number of documentation files that can be handled as a single collection (QTBUG-59664). Given the symptoms when that limit is exceeded a similar issue could well exists on other BSD variants too. I'd be interested in participating in this project.
An additional feature that should probably be considered and copied from Qt's Assistant (also for general usability) is support for tabs, so users can switch quickly between different documents.