I don't recall seeing any argument for s-risks being a particularly plausible category of risks, let alone one of the most important ones.
There was some discussion back in 2012 and sporadically since then. (ETA: You can also do a search for "hell simulations" and get a bunch more results.)
I never saw anyone draw the conclusion that "hey, this looks like an important subcategory of x-risks that warrants separate investigation and dedicated work to avoid".
I've always thought that in order to prevent astronomical suffering, we will probably want to eventually (i.e., after a lot of careful thought) build an FAI that will colonize the universe and stop any potential astronomical suffering arising from alien origins and/or try to reduce suffering in other universes via acausal trade etc., so the work isn't very different from other x-risk work. But now that the x-risk community is larger, maybe it does make sense to split out some of the more s-risk specific work?
I've always thought that in order to prevent astronomical suffering, we will probably want to eventually (i.e., after a lot of careful thought) build an FAI that will colonize the universe and stop any potential astronomical suffering arising from alien origins and/or try to reduce suffering in other universes via acausal trade etc., so the work isn't very different from other x-risk work.
It seems like the most likely reasons to create suffering come from the existence of suffering-hating civilizations. Do you think that it's clear/very likely that it is net helpful for there to be more mature suffering-hating civilizations? (On the suffering-focused perspective.)