Please improve Withered Effect (skill tree)

Withered Effect are two skills (top right on skill tree) that increase the effect of Withered by 10% each (so 20% in total). The issue is, the math is like this:

- Withered = 5% multiplied by stacks (max 50%)
- With 1x Withered Effect = 5%*1.1=5.5% -> round down = 5% multiplied by amount of stacks (max 50%)
- With 2x Withered Effect = 5%*1.2=6% -> round down = 6% multiplied by amount of stacks (max 60%)

Do you see the issue? The first skill could also be labeled as "skill that does nothing" while the second skill "increase Withered by 20%". So players who just have one point left and put it into the first Withered Effect (or stuck long time on level 90+ before they can skill the second point) are fooled by this game rule.

There are tree possible solutions:
1) Just do not round this value at all, so that Withered can stack 5.5%, 11%, 16.5%, 22% etc
2) Round down after all stacks are applied, so that Withered stacks 5%, 11%, 16%, 22% etc
3) Change the first Withered Effect to something else and apply 20% to the second Withered Effect or anything in this direction that does not make the first skill pointless.

PS:
That is a kind of game design behavior that should not exist in any kind of game, even if it is no critical or even important thing.