I agree. You can run a few degrees more exhaust side but only past the trq peak. That might help you out a bit but not much. Dont go crazy with the intake cam advance. The stock map is not bad. There are some things I do between the cruise and accel maps. But Your not going to find big power gains here on your 08. When we start changing turbos and engines where my experience comes into play with these maps. I have hundreds of hours of chasis Load dyno experience with tuning those maps and I have come up with some favorites over the years and I stick to them.
Adjusting the advance and retard and moving seperation of cams is what we call Dynamic compression in the industry. Sometimes also called Running compression. This is something that needs to be understood. If you alter the dynamic compression of the motor, Your timing map is likely no longer valid.
Do not over advance your timing off boost. That is one of the biggest mistakes noobs make. Timing is not a volume knob for power and only has one correct settting. Comments like "conservative timing" is a red flag for someone that does not know what they are doing. Its easy to blow a motor and crack a piston "OFF boost" by creating preignition. You get light det during cruise and tip in. Your ring lands and rod bearings suffer.