Nostalrius Begins - Quality wow vanilla realm (1.12)

Idol of Rejuvenation (the druid item which adds another +50 to heal on Rejuveation) is currently not working as intended. Instead of giving "up to 50 bonus healing" (in this case increasing your total +heal stat for this spell by 5+) as the item says, it adds another 50 healing to EACH tick, effectively making the item way overpowered.
Steps to reproduce:

1. Unequip all items.
2. Use Rejuveation and check how much it ticks for.
3. Equip "Idol of Rejuvation" and repeat step 2.

We didn't manage to find any solid proof about how this item should work. So if you can provide us official sources, we will change it as soon as possible.

Just like every other +spelldmg/+healing item, it says "by up to XX" which means it is effected by each spell's coefficient. HOTs/DOTs generally scale with ~80-100% (might differ depending on amouint of ticks) of spelldmg/healing, but is divided by the number of ticks.

For example, if a DoT ticks for 200 x 5 ticks base damage, and the character has 250 +spelldmg, the dot will do (250/5=50) more damage per tick = (50x5=250) more damage total. The same goes for healing

Assuming your Rejuvenation coefficent is correct, the idol should increase each tick by (0,8x50)/4 (12 seconds, 4 ticks).

Here's some old forum thread regarding the issue. Nothing official but I feel this one is fairly obvious http://thedruidsgrove.org/archive/wow/t-10563.html

Fixed.

I'd just like to add, in case it was overlooked, that the "source" suggests that the spell really gains +50 healing total, and not 0.8x50=40 as I said. I don't think there's any way to prove this, nor does it really matter, yet it might be worth mentioning.

We fixed it by adding 50 to the total of the spell and not like it was 50 healing spell. As explained in the link you shared.