Subjectively I would put full reverse at under the A/B2 mark overall, but the idea is simple:
If you use full reverse and a/b you SAVE brake wear but still get the benefits of early brake application, even left and right application, aid in crosswinds, a guaranteed deceleration for exit planning and a 'banker' in case reverse is either slow or does not function properly. Cannot see the problem.
Regarding max manual, I was once passengered into Ronaldsway in a 73NG by an anxious Captain who set A/B max, could not get it to disengage, pushed everyone's nose into the seat in front and stopped half-way down the runway. I was in 1C and practically doubled up against the partition. There was near panic in the cabin.
