why you need a preview of the other layers ? you can't just watch them normally ?
Time ago here i played with O with some tweaks of a cool tutorial of RobA , and some derivates of his "environmental map" because one of the most cool effect of the filter come to use a enviromental map
(that can be chosen in the opened image....if i remember well should be another single layer image not a layer
i still use a copy of that map as Map for M3D let'me found it..it is my map 111 (because 111 is easy to remember ...here it is but all merit is from RobA
oopps maybe it is not the original but anyway close should work fine for gold effect
maybe even this would do some gloomy effect ?
not yet tested...