The statement is somewhat self defeating in that in general big power comes at high revs with the RB26.
I would also suspect that high revs probably contributes the the breakage of rods as much as the torque stresses.
Anyway, as a guess, I would say if you select the rods carefully and prepare/check thoroughly (crack test, shot pean, linish), I would suggest that you would be safe for any low mount application.
For twin high mounts/big single, you would be pushing your luck over time.