Hello, I haven’t found anything on the subject and I’m wondering what’s better for a dual Mosaic PS sin?

Let’s say the build goes like this:
-20 PS (using 2 charges)
-20 Claws of Thunder (using 3 charges)
-20 Tiger Strike (3 charges)
-20 Blades of Ice (3 charges)

Leftover points going into one point wonders, some Fist of Fire being careful not to exceed the lvl 34 skill so I can leech, some points on Dragon talon to reach desired number of kicks.

With that setup, is it worthy to put a LSunder charm or is it best to fit that slot with a skiller? Taking into account the damage type mix, my reasoning it’s telling me that the skiller has the upper hand.

Drop your insight here about this. Or if this have been discussed, share the link with me.

Also if you have any comment on the setup above, you should let me know.

TL;DR: Is it worth using LSunder on dual mosaic sin or better slap an extra skiller?

Oh, and also, how much of a difference can +3 PS OR (not both, that’s hilariously expensive) +3 CoT bases make on the overall damage? Is it really evident? Or just min-maxing?

Thanks in advance!