The best combination I've found with this paper is Ilford Harman Cooltone developer then selenium toning. The cooltone developer produces pretty much neutral shadows and the Harman selenium (at 1+9) then produces really deep, dark shadows with only a hint of reddening if you leave the paper in the selenium for a long time.

Unfortunately Ilford Harman Cooltone has been dropped but there's still a little left in the channel if you search around.

I had hoped that Dokumol would be a good replacement developer but it produces noticeably green tones.