Rare titan bonus roll - still at 0 drops

[Gryphonknight]

@DBC

The more stars a rare has the more likely the bonus item is to drop.

I agree.

@Kerridoc

someone usually gets the bonus loot off our 12* rares.

The Devs gave us vague hints

* Rare Titans have a bonus chance for dropping a specific 4-star ascension material. The bonus chance is affected by how many stars the Rare Titan has. ( Linky, linky)

But still unsure what determines it

(Rare titan bonus prize – how does the chance for the extra loot work? Who gets the extra item? - #45 by Gryphonknight)