Eventually every bundle will be available on the ChimeraX toolshed, not just 3rd party bundles.  This will allow bug fixes and improvements to non-core parts of ChimeraX to be distributed incrementally and immediately and not require an entire re-install of ChimeraX.  The toolshed uses standard wheel format for distributing packages and therefore wheel packaging is integral to ChimeraX and there is no provision for non-wheel builds.

—Eric