I use ceramic rope now as my wick of choice and have a .8 coil on my evod.I still have silica wick laying around and do use it sometimes but prefer the other.I do not even worry about whether silica is bad or not,i smoked for 35 years so worrying about silica,nope.I will not keep my coil at .8 in this evod because the silicon gromet that sits on top of where the post covers the coil,melts,and burns with the heat build up.I do not get any funny taste from it but you can see that it has changed color from white to brown.I do not see it as a bad idea to wrap a SLR coil in the protank or any other rebuildable.