What benefit would the APR Fuel pump upgrade give to the JKM stage 2 setup?
As far as I understood this upgrade was only needed if you wanted to go Revo's Stage2+ software.
The FP upgrade (as I understand) may be particular benefit if you experience fuelling issues sometimes due to a setting in a tuner's remap (too high a Boost setting perhaps). This would also show by a dip in the power curve and, I assume, in data logs - Please bear in mind I have limited knowledge in this.
As I understand it, a Stage2 remap might put demands on the FP which the stock one would have difficulty in meeting. You would feel it when driving - Interruption of power when under load or even misfiring.
Currently, my Stage2 is plotting a very minor dip (but no driving issues) and so could be improved with the APR FP.
I hope this helps.