No reason whatsoever why the ETO ones shouldn't be just as easy to modify as the stock ones. I've modded enough of them, one way or another... As noelberrier says, you've either forgotten to delete the bdp, or there's a spelling/syntax mistake somewhere. ETO and MAW aircraft are simply CFS3 aircraft - no secret tricks, just more developed effects, etc. They still work the same way, even though the information contained in the xdp is more evolved.