Thorn bikes are now adding reinforcing flanges to Rohloff hubs used on their tandems [see photo below]. I’ve also read that they are drilling Rohloff hubs for 48 holes for tandem use. So you could get a 48 hole Rohloff hub with flanges added…probably total overkill, but I’m sure someone will want one!
I should point out that I’ve been using a standard 32H Rohloff on my Surly Big Dummy under massive loads and had no issues. I’m not suggesting getting your Rohloff drilled for 48 holes and/or adding extra flange reinforcement is needed except in the most extreme circumstances.