Since these are Direct Calls, then that should mean that you have 4 different _satellite.track() calls in your web page(s). Is that correct?
If so, you could try this:
- Study your Direct Call triggers to find out their firing order. I have a feeling that the Direct Call triggers are not happening at the same time.
- Based on their orders, remove the "Send beacon" action from the 3 Direct Call rules that are fired first.
Then, when the 4th Direct Call event gets triggered, it will run the "Send beacon" action. That action would be able to send the data that had been set in the eVars by the first 3 Direct Call events.