Generate JWT tokens without using bloated zfj-cloud-rest-client-1.2-jar-with-dependencies.zip

I'm trying to communicate with the Zephyr REST API. I'm creating test suites, test executions, etc. It works fine except I'm currently using the bloated zfj-cloud-rest-client-1.2-jar-with-dependencies.zip as a dependency with the ZFJCloudRestClient class. As folks are likely aware, I had to manually install this zip into my maven repo in order to get it to work since it's not available in any centralized maven repo, which is super gross. Additionally, the contents of the zip include a BUNCH of crap that looks unrelated to the single generateJWT() method I'm using. I've also tried to use this jar (https://github.com/jenkinsci/zephyr-for-jira-test-management-plugin/blob/master/src/main/resources/zfj-cloud-rest-client-3.0.jar), but it seems to be missing dependencies and uses some weird typesafe.play classes. Why is this so hard? It seems to me that there has to be a fairly strait-forward way to create these JWT tokens if we understood what params and such were needed. The code shown on this page, https://developer.atlassian.com/cloud/jira/platform/understanding-jwt-for-connect-apps/, is nearly it, but I haven't been able to get that approach to work either. I'm hoping someone out there has solved this.