Hey there - I tested conflux scaling with a dedicated but fairly cheap prebuff setup.
You can have a look at the used items - here
It includes upped Laz and Void trophy but no Dim Key and no +skill jewels and no skill shrine but apple prebuff with
DestinySpirits of the Nephalem
Gilded Shield (Sacred)
Defense: (8868 - 9976) to (10992 - 12366)
Chance to Block: 1%
Required Level: 100
Required Strength: 700
Item Level: 1
+2 to All Skills when using an Apple
+3 to Barbarian Skill Levels
+(41 to 50)% to Summoned Minion Life
+(11 to 15)% to Summoned Minion Resistances
+(140 to 170)% Enhanced Defense
+2% to Runemaster Defense Bonus
Maximum Mana +15%
Regenerate Mana +(31 to 50)%
(Barbarian Shaman Set)
The pierce seems to have dim return scaling but it does not really fall off that quick.
With base lvl 30 on Conflux the Life on Melee attack scales like 9.something / slvl.
I think the endgame scaling of this skill def needs some downward tweaks - especially because with 10 minutes uptime it is totally worth it to put together some prebuff gear for special encounters.