The Shadow "knows"

[Crystalion]

It gets even better if i'm a decked out trapper.. traps can be above level 30, meaning you're looking at 30/2 + 26/3 or even higher, which leads to traps being laid > level 20 by your trapper!

Yes.

But keep in mind that you need to train/"burn in" the shadows memory for synergies. I still don't know if it is sufficient to do something less involved than having the shadow cast a skill, I just know that that works.

But I've neither done the testing or code-reading to be aware of any slvl caps that might be in place.

That is, the supposed "20" cap for synergies--which actually doesn't appear to exist, given the whole marrowalks cheese--and perhaps a cap for shadow skill levels, ala caps for hirelings.

But there is also no evidence I know of to suggest these caps might exist, so, as usual, more testing is needed. ;)