In doubt.
That approach would have saved me HUGE amounts of time last saturday, but I refused to do it... Was matter of principal, but there is a bit of remaining frustration lingering there :-)
Saturday I figured the subproject was named "agenda", not "jfxtras-agenda", and stubbornly stuck to that. However in Maven I like artifacts to be prefixed with their project name, so I modified only the artifact names. But if that choice is causing more problems besides the Maven artifact id, I think renaming is a good idea. Do remove the prefixing in the build.gradle file.
Tom