I’ve answered my own question so I figured I post my findings.
I have replaced the 120mm Reba SL Maxle with a 150mm Revelation Team U-turn Maxle fork. The Black Box damping in the Rev makes it a far better fork.
I never noticed the flex and twang of the Reba on the Rev because the damping works so much better that the fork is doing it’s job rather than locking up and generally a being a bit crap in the gnar.
Even at 150mm the Rev feels stiffer in the gnar than the Reba did at 120mm. The better damping in the Black Box Team fork makes the difference in the gnar, IMHO, YEMV, etc.