Patch 0.3 introduces several pinnacle boss changes that will both increase the availability of the boss encounters and increase your ability to push into content earlier.
Version 0.3: Pinnacle Boss Changes
Overview
Guide
Pinnacle bosses no longer required to unlock passives
The first set of Atlas passives no longer require pinnacle boss kills. These first two passives now come after completing some component of the relevant content in the endgame Atlas.
For example, to acquire the first two Delirium passives you need to find and kill Omniphobia or Kosis, the two Delirium bosses that spawn in maps, instead of completing the first set from a Simulacrum.
Pinnacle bosses now have tiered fragments
Previously the value of boss fragments were strongly correlated to how good the rewards were for the most difficult version of the boss, meaning you were incentivized to sell the fragments instead of run them for yourself to progress your own Atlas.
Now each difficulty of pinnacle boss encounter will require differing amounts of the splinters themselves.

You can choose to tackle a tier 1 boss by using 50 splinters, as shown above, or choose a more difficult challenge by using 100.
Atlas passives no longer increase boss difficulty
With the change to boss tier correlating to the number of splinters consumed, this means the small travel nodes in your Atlas Passive tree no longer increase the difficulty of the Pinnacle boss. Instead they will grant content appropriate bonuses.

Arbiter and Uber Arbiter
Arbiter no longer scales difficulty with Boss Atlas passives, and instead has been reduced to two difficulties. Arbiter and Uber Arbiter. The encounter still requires Crisis Fragments from the Atlas Citadels, however now you can drop Calamity Fragments by completing your full Boss Atlas Passive tree and then completing Citadels.
Once you've acquired the new Crisis Fragments from a fully filled out Boss Atlas Passive Tree, you'll drop the new fragments into the same interface after clicking the checkbox below
