I think this is a very interesting topic for advanced users with Playmaker that we are just not so familiar with coding in C#. I struggle many times trying to call functions from other plugins and make them work using Playmaker. It would be nice to have some tutorial with an example case about how to create custom actions to use with other plugins.
(Like, I have this inventory plugin without support for Playmaker... how we make the custom actions for it so I can add/remove/use items?)