26bps was the recommended adjustment based on historical analysis at the time. The actual spread in the market is not a constant, and has been below 26bps for a long time. The current LIBOR-SOFR spread is around 12bps. It's all negotiated, so people who earn interest are arguing it should be 26bps and people who pay interest are arguing it should be 12 bps. The market seem to be settling on 3M LIBOR = 3M SOFR + 15-20bps.