Falling Zombies 2.5x damage scaling, is it just melee physical or overall damage?

I'm trying to POB right now a COC Falling Zombies with Minion Instability and I'm not sure if the 2.5x is just physical or overall damage.

ANY Dev that can confirm this?

How to POP the Zombies:
60% Minion Taken Damage from Fortress Covenant
29% Taken as Fire Damage Replica Earendel's Embrace + Infernal Legion
Maligaro's Lens With Necromantic Aegis.

Already answered. Compared to a normal attack, a ground impact attack deals 2.5 times the damage.

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How much damage does Raise Zombie of Falling's impact attack deal?
It deals 2.5x the damage of a regular zombie melee attack.

https://www.pathofexile.com/forum/view-thread/3452002#18