Ultimatum not prioritized in Mirage

I am finding less and less Ultimatum encounters inside the Mirage. In my last map, the Mirage had no extra content inside. I have an atlas tree that is only Ultimatum with all other content blocked.

Bug Report ID: #4,244,546,459 - Mirage side area
Bug Report ID: #3,835,482,917 - main map area

You understand that mirage works on mechanics within its proximity, right ?. So what probably happens is the map you run is so big, mirage spawns too far from ultimatum hence ultimatum doesn't make it inside. That's not a bug, that's literally how it worked since the beginning.