[michaelneale]

It may not work for you but "organization folders" (a feature of multi branch) were designed to discover projects from bitbucket, github etc (ie a new repo appears, with a Jenkinsfile, a new project will automatically configured). Some people have had luck with them (they don't always work how you want though, but when they do, don't need to manually create the pipeline other than dropping in a Jenkinsfile in a new repo).