We are a team of senior CS students from Western Washington
University, and we are currently working a project to implement the
enhancements to inetd as described here:
https://wiki.netbsd.org/projects/project/inetd-enhancements/
When it comes to adding per-service configuration files, our current
plan is to add a new configuration command, simlar to xinetd's
"includedir", that allows for specification of a per-service
configuration directory.
Personally, I think this is a bad idea, most fundamentally because it
enables, even encourages, administration without understanding.