I have toned a lot of Ilford WT in selenium, though mostly FB paper. I have always found the problem you have too. In my experience there is very little difference in what developer you use. Maybe back in the old days, like before 1990, you could impact the color of the print significantly, but now most papers don't respond much to whether you use Ansco 130 or Amidol or any of the various WT developers. If you leave the print in the toner a longer time the split will go away but it will all be that reddish brown color... that some people love. If your prime concern is print color, you might try using Neutral color paper and then tone it with Bergs brown toner. It will still go brown but it won't have the reddish cast. It is worth a try.
Dennis