Manabond with Spell Cascade doesn't overlap

Manabond - circles barely touch

Other skills - circles clearly overlap


I tested it with life on hit (i don't have regen, so it's easy to count hits)
It hits only once most of the time. If you manage to target exactly in the middle like this it either hits twice or doesn't hit at all, probably depending on angle or whatever.

This is likely intended behavior, spell cascade tries to place spells so there is minimal overlap

https://www.pathofexile.com/forum/view-thread/3414799/page/6#p25068804

above is talking in relation with curses but Mark does go over the intended behavior of spell cascade in general.

I've heard about that fix.
From my understanding intended behavior for Spell Cascade is 2 overlaps, i'm not asking for 3. It is how it works with other skills. Otherwise what is the point of it?
I can guess that it doesn't work with Manabond because of this line "+6 to length per 25% of Unreserved maximum Mana you have" and it was "fixed" to spread based on having extra AoE at 100% mana.
First of all, why does the skill that scales base damage from missing mana scale AoE from current mana?
And if i am at ~0% mana why does Spell Cascade spread based on extra AoE that i don't have?