[Skill] Blood Hunt

I'm looking at the new spear skill Blood Hunt.

Specifically, I'm trying to determine the design philosophy, in addition whether to continue using the skill.

I noticed that leveling may reduce the effectiveness of the skill. The idea is to consume Blood Loss (a counter of all phys dot from full health or since consumed) to do a blood explosion.

The effect is kinda neat. However, leveling it appears to reduce the ability to scale the AoE size. At lvl 7, it gets 10% more AoE per 18 consumed Blood Loss. At lvl 9, that becomes 10% more AoE per 37 consumed Blood Loss. The base damage goes from 170% Attack damage to 196% Attack damage (each before getting a bonus of 25% of the consumed blood loss).

So my concern is that, given an equivalence in all other factors, it scales AoE worse as it levels. Is that the case and, if you have insight into the dev thought process, is that lack of clarity intended?