Sorry, but I don't understand, maybe I'm missing something. To run application with Plugins, you have to build them before launch. After succesfull build, you will get compiled plugins. Then if you want to change something in the plugin, you will have to open source code, change the code, then again Build the plugin. It's the way how it works.
Okay, I've built each plugin, now when I launch grandnode I can see them in the 'local plugins' tab. However if I click install on one of them, I see 'plugin installed' message, but plugin still appears in the 'not installed' list and it's not actually installed.