reduced reservation efficiency with two Essence causes infinite mana reservation requirement

I tried to use two aura in 2 Essence Worm, and a third one but after wearing 2 of this ring the mana reservation of the third aura is Infinite.
I tried it with a lvl1 Vitality what reserves only 28 mana, but it also want to reserve infinie mana.

I saw in poe wiki that the mana reservation is calculated like this:

mana reserved = base reserve % / (100% + total reserve efficiency %)

With two Essence Worm the result is based on the above equation:
For example the "base reserve %" is 50% (Pride)
The total "reserve efficiency %" is -160%, because of the two Essence Worm

mana reserved = 50% / (100% + -160%) = 50%/-60% = -5/6 NEGATIVE

I think the way how the mana reservation is calculated is wrong. Before the reservation efficiency was released I was able to use third aura with two Essence Worm.

Please fix this. I don't think the mana reservation should be caplculated like this. In this way increasing mana reservation efficiency is logarithmically scaled, but the decreasing reservation efficiency is exponentially scaled. There is no balance between the two.

The below caplculation way is more acurate:

mana reserved = (base reserve % + total decreased efficiency %) / (100% + total increased efficiency %)

If you use the recommended equation, it is more balance between increasing and decreasing the reservation efficiency.

It is not a bug.

Just one Essence Worm already cost you to not able to use herald already due to 125% mana reservation.


It rather a design fault that just ez rework that the old "40% increased reservation" mod was just times 2 and flip the direction as "80% reduced mana efficiency". This is observed elsewhere that quite a lot of mod just times 2 and flip direction. Only a few has exception .

But in fact the item should balance individually to have lower reduced efficiency value