There are two possible scenarios I can think of how it could work:
Scenario 1: If I get 1 ruby from an outpost rush, no cooldown gets triggered. Only if I finally get the second Ruby, even if it’s days later, I have to wait 18h to get the next ruby drops.
Scenario 2: The 18h time frame starts with the drop of the first ruby. In this time frame I can get up to two Rubies max. And no matter if I get the second ruby or not in that time frame, after 18h the “cooldown” is over and I can get 2 rubies again within an hour if I want, triggering the next 18h time frame with the first drop.
Which scenario is right? 