Works with crits also.
I'm unsure if it works with WS, but would doubt it (hard to notice on multi-hit WS)
OK, I'm just done with solo KI farming in Misareaux.
One time I did 3.3k evisc on Manohra, it gave me 12 TP return
and next 2 birds after I got 3.1k evisc with 17 TP return.
Now my WS gear only has 21 store TP total during WS (i.e. coefficient = 1.2)
and have a total of +40 DW (traits, +2 body), which brings my dual Kila +2 TP per hit to 3.7 TP*1.2 (STP) = 4.5 TP/hit),
So 12 TP return is actually just come from main + offhand + 3 hits landed. Yet, that is the highest Evisc I got that night on Frigatebird. I think it's very likely AF3 +2 effect can proc in WS.