Lunar Blessing not receiving correct duration from Skill Effect Duration

Lunar Blessing has a base duration of 5 with .2 seconds added per Rage spent to cast it.

With my max rage, it ends up at a 15 second duration, but with Prolonged Duration II socketed into it, it only goes up to a 17 second duration. 32% Skill Effect Duration from the passive tree also only gives 2 extra seconds.

Skill Effect Duration is only adding on from the base 5 second duration instead of the total duration after Rage is factored in.

I also would like to know if it's intended for the passive tree to show skill effect duration having no effect on skills like lunar blessing?

Pressing alt shows it affecting no skills, even my spell skills. But given this passive node I am using is called blessing of the moon surely it was intended to be used for this purpose?

yeah for now i removed the "skill effect duration" passive skill tree points as makes no sense to waste that much point on it. second wind is good enough with rage and prolonged support.

The base 5 seconds is getting increased from duration support gem and increased skill duration.
But the increased duration gained from rage does not seem to scale with increased effect duration, nor does it scale with the prolonged duration support gem.

My current Lunar Blessing lasts 22 seconds, which is a lot less than i expected.
Here is how it seems to be mathing out:

I currently have +86% increased skill duration from my passive tree and jewels.
I currently have a maximum Rage of 48. For a total of +9.6 seconds onto Lunar Blessing from rage.

Lunar Blessing gets its base 5 seconds x 1.86 for the increased skill duration for a total of 9.3 seconds. Then that gets multiplied by 1.35x from Prolonged Duration II support for a total of 12.5 seconds. Then, the 9.6 seconds from rage is added onto that for a total of 22.1 seconds.

The duration gained from rage does not scale with any duration increase stats.
Which is pretty lame because pressing this button every 20 seconds gets old real quick. I can run around on my bear with Calamity on for like 45+ seconds at a time. I hope this is a bug, and not intended because its really disappointing leveling my wolf and being excited to get this skill only to find out that even after they changed it, its still disappointing.

If the rage portion of the duration was being scaled, my skill duration would be at 36 seconds instead of 22 seconds.

Either they need to make the rage portion scale, or they need to slightly increase the base duration from 5 seconds to like 8 or 9 so that it has more base to scale with duration sources.
As it is right now, the maximum duration you can expect to see on this skill is around 28-30 seconds, and that is with like maximum investment. If they increased the base duration from 5 to 8, that would go from 28 seconds to about 38-40 seconds with high investment.