The SLS uses old Shuttle SRBs.

I assume the same ones with the post-Challenger 3-ring redesign that doesn’t fix the core problem at all.

Jesus. Add it to the list of safety-related reasons I hope that nonsense project never makes a crewed flight.

After reading TFA I also have this question: are the SLS boosters also using this 3 o-ring design?

SLS uses improvements made late in the Shuttle program. Lower temp materials and some larger diameters. Presumably that exact problem is fixed. Others? Who knows.