Question about stereo FX returns

Is it correct that when using an aux send to a stereo fx that the FX portion is returned to the center position (assuming the pan on the return channel is a center) giving the fx portion of the signal hard left and right positions even if the original track is panned say 70% left? I use a lot of stereo aux sends for adding a bit of verb or delay to multiple tracks but it often tends to muddy up things somewhat quickly even with high pass filters. I believe it may be from the previously mentioned situation. If I use mono FX in the aux bus it will still return FX portion of any tracks sent to it to a single stereo position. What are good practices to use to avoid "cluttering" the stereo image?