PNG in XWE

When importing a PNG into XWE, is it possible to stop it converting it to the Doom Pallette as I have been lead to believe that PNGs when used in sourceports that support them allow full colour (that is not in the doom pallette).

http://slumped.mancubus.net/

Use Load (raw data).

which ports are PNG compatible with?

Apart from GZDoom and Skulltag (already mentioned in another thread) there's Doomsday Engine, Vavoom, DelphiDoom and Risen3D.

EDIT - Don't know for sure if all of them support PNG's in wads.