not sure of the point your making in this post, if your saying revo poss max out injectors on stage1 then adding a free flow exhaust doesnt then increase your injector flow more, and same with intake ect. stage 2 and 2+ as you know arnt just parts added its software as well and imo would be more fuel at different points in the map/rev range.
my point is there must be "headroom" on stage one for them to request more for stage 2 and 2+
hope that makes sense.
but stage 2 takes into account a more efficient exhaust, so less restriction = more power but not necessarily more fuel. Add an exhaust and your exhaust gas temperatures will reduce so they can run slightly higher boost as well.
Stage 2+ takes into account the higher efficiency of the exhaust and intake, and advances in ignition timing due to the cooler inlet charge from the intercooler, so not necessarily more fuelling.
Each time you add these bolt ons for stage 2 or 2+ the newer maps dont necessarily ask for any more fuel than in stage 1, but they ask for more boost or timing as the new mods will allow the more aggressive setup and thats where you getting the extra power.