Customising the pom created by the Plugin Publish plugin

Thanks @twwwt, I am aware of that but it does not help with the Plugin Publishing Plugin.

Btw, you could use this syntax which I find more readable (credits go to @daz, see New publishing model and POM customization via XmlProvider) :

def pomConfig = {
    description project.description
    inceptionYear project.ext.inceptionYear
    
    organization {
        name project.ext.organization
        url project.ext.organizationURL
    }
 
    ...
}

publishing {
    publications {
        mavenJava(MavenPublication) {
            pom.withXml {
                asNode().children().last() + pomConfig
            }
        }
    }
}