You dont want to lift before rev limiter, as the tuner want to see how the engine is performing under full load ie full throttle), right up to redline.
While second gear is ok and reliatively legal on public roads, it probably better to do runs in third or even fourth gear it the car is going to be tracked, usually this requires a dyno or a racetrack but its usefull to gather that data. As the actual loads and duration of load on engine is different to say lower gears.
Note that what is refered to as "load" in Subaru ecu is not actually load it s a derived parameter based on air flow and rpm, not actual load
http://www.romraider.com/forum/viewt...hp?f=15&t=8218