I'm used to launch two instances of mt-daapd (http://www.mt-daapd.org/) service, to workaround a design limitation of that software (need all the shared files to be on the same filesystem). Launching two separate instances of mt-daapd (on different ports) in the same machine works fine with the internal responder and when using a normal howl responder, but it does not work when building against avahi with howl compat.
The HOWL API is broken when it comes to name conflicts. Please port mt-daapd to our native API and your problems will go away.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.