Hi everyone,
After working on this system for a while, I finally managed to achieve what I wanted, and it makes the editor much more powerful for creating complex gameplay logic.
First, I added an Action system where multiple Actions can be attached to an object and automatically combined. You can add as many Actions as you need.

For example, adding several Actions:

But that’s not even the most interesting part.
I also added a new special Behavior script called MultiBehavior, which allows multiple Behavior scripts to be attached to the same object.
Before this, an object could only have one Behavior script, which was becoming a limitation for the type of systems I wanted to create.
Now it looks like this:

This Behavior is simply a container. It provides a button that allows you to add as many Behavior slots as needed, and each slot can contain another Behavior script.
For example:

On the game side, when this Behavior is triggered by an object connected to it, MultiBehavior simply executes all attached Behaviors.
All the different systems can therefore allow several interesting things.
Action ➜ Reaction ➜ Reaction ➜ Reaction... (chain reactions)
Or:
↗ Reaction ➜ Reaction ➜ Reaction ... (chain reaction)
Action ➜ Reaction ➜ Reaction ➜ Reaction ... (chain reaction)
↘ Reaction ➜ Reaction ➜ Reaction ... (chain reaction)
Or:
Action ➜ (Reaction & Reaction & Reaction) ➜ (Reaction & Reaction) ➜ Reaction...
Or even more complex combinations:
↗ Reaction ➜ (Reaction & Reaction & Reaction) ➜ Reaction ...
Action ➜ Reaction ➜ Reaction ➜ (Reaction & Reaction) ...
↘ (Reaction & Reaction & Reaction) ➜ Reaction ➜ Reaction ...
Combined with the existing object connection system, this gives a lot of flexibility for creating interactive environments.
I plan to release version 3.1.0 in the next 1 or 2 days.