I think using the setting, and maybe one or two companions from the original game, along with tying up some loose plot threads that were more tangential to Planescape Torment would be a very satisfying way to engage the Planescape IP. Avoiding being a direct sequel to Torment while still adequately calling back to what Torment did to make the property good. Bring in Nameless Origin Characters whose different lives you slowly unravel. But leave the continuing story of the Nameless One and the rest of the companions very, very vague, if it has to be in the new property at all.
I agree 100%
