If any of you were interested in this topic:
Creating and manually firing VMF-like output connections
Then I've got a demo tutorial for potential map creators. The video demonstrates:
1. How to use use virtual plugin entities in Hammer editor
2. How to compile the map with VMF preprocessing
3. Generated JSON-file with data that plugin will later use
4. Actual gameplay
I'm sorry for the video length (25 mins), but you can safely skip up to 23:00 if you're not interested in making maps. Though it might be interesting.
Thanks.