Yeah I’m not sure why you would want to do this in the first place. That’s a very roundabout way of distributing something internally.
If you’re using the precompiled engine directly from the launcher, you know where the install path is and can either have people copy paste your plugin folders to “install” them, or you can write some very simple automation tool to do it from an intranet web page or something.
If you’re using the engine from source then you already pretty much have a source control solution and can just add your library of plugins in your depot under your /project/plugins folder. There’s no reason to not just have them all installed all the time, just keep them disabled by default if the functionality you want is for people to opt-in to certain plugins (if your workflow is to have lots of smaller projects with different needs).