Would it be possible to look at distributing Logstash plugins via RPM? The majority of corporate RHEL estates, in my experience, don't permit external access unless a server is required to face the internet. The general rule is that software must be installed from sources inside the corporate firewall.
It would make a big difference if plugins could be built, packaged, and distributed as RPMs. This would allow Admins to download the specific RPMs that they need and include them when installing the base Logstash RPM.