Hello, I am trying to read the state of the plugins found under “Edit”. I use Glyphs.reporters for reporters, Font.tools for tools, but what do I use to find plugins that live in Edit? I want to check if a specific plugin is currently running, ideally also shut it down if it is currently running.
Any help much appreciated! Thank you 
I can’t give you a list of those. That are “general” plugins that decided to add a menu item there. You can use this to get to a full list of those plugins:
print (Glyphs.delegate().valueForKey_("pluginInstances"))
What do you need them for?
I have some scripts that work with Kern On and I want to make sure that Kern On is not running when the scripts are executed. So at least, I want to give a warning to the user that Kern On should be closed before running the rest of the sript.
You should use check if the KernOn plugin is loaded by doing something like this:
if objc.lookUpClass("KernOnPlugin") is not None:
But that doesn’t tell you if it is active or not.