What of the Warper?

I was just reading some old posts about the Spell Weavers and the Ethergaunts and that reminded me of another mysterious, superintelligent race from long ago and/or far away, one that I know next to nothing about: The Dimensional Warper. They appear in the Forgotten Realms 2e MC appendix - the very first paragraph of their entry concludes with "The dimensional warper has never been encountered on the Prime Material Plane," and the second paragraph immediately begins explaining how dimensional warpers sometimes visit the Prime, so that's weird, but they're generally presented as relatively powerful extradimensional seekers of knowledge. I know they don't show up in PS and google didn't help me out much - does anyone know any canon surrounding these creatures?