Patch 10.2 adds some interesting trinkets to the game and the latest discussion revolves around Augury of the Primal Flame.

In addition to the latest feedback about Nymue’s Unraveling Spindle and Rashok’s Molten Heart, Blizzard also talked about Augury of the Primal Flame.

(Source)

Augury Notes:

Damage scaling seems correct, but how that interacts with the cap is unclear. Tooltip states this limit increases per enemy struck, but in practice it does not appear to be working as expected.

Without a tooltip value indicating how much is left on the limit this is tricky to calculate

As you add targets the limit is not behaving predictably, and sometimes is ending much earlier than expected (buff expires before enough damage has been dealt)

RPPM is still flat and not hasted as indicated in an earlier post

Damage and the cap scale at the same rate

This is useful feedback when it comes to interacting with the trinket; the tooltip will display the remaining damage in the next PTR update

We’ll look into these issues as potential bugs (thanks for the reports!)

The RPPM change was made too late to make it onto the current PTR and will be reflected in the next update

As far as any modifiers go, I can see that the tooltip is misleading as-is; it has been updated to better reflect the mechanics. You can think of the cap like any other damage trinket effect when it comes to scaling with Critical Strike and Versatility. As you would probably expect, these modifiers are taken into account after the damage cap calculations so that the overall potential damage can scale in the same way as a trinket like Beacon to the Beyond.

In addition to the above changes, the duration of the buff has been decreased to 20 sec to reduce the chance of overwriting itself while the bonus critical damage has been increased to 50% to offset this shorter window. It’s not intended that players necessarily get the full value every time the trinket procs (i.e., during the lowest DPS troughs for certain specializations with low Critical Strike rating), but it should feel easy to achieve during burst windows and reasonable the rest of the time. These values will be further adjusted as needed to achieve these goals.