I have not checked a single cam 6. I have not rechecked either of the 4 cam engines I am driving since they were setup. Not that my 3.8 has any miles on it, Damn where did I put that title, Damn.
Most of the roller cams are asymmetrical lobes. I would not expect to find wear on a cam lobe.
I would however check both sides and from what I have learned with the 4G63 the belts settle in a fair amount. I found a set of cams rolled back almost 4 degrees in the first 1000 miles. That was not a factory belt not that this matters.
I now run the engines awhile before setting the cams. That would suck with the accessory mounting and blower drive on your engine.
Also the followers run on an odd path and move a degree or two through there range, I have not confirmed this myself. If your checking spring is soft enough and the lifter has heating oil in it they should respond fine during this work. Wait delete that thought, that pertains to the DOHC engines.
Sorry your sets up the same as a 2.6, again the lifters should have fuel oil in them and I use a shortened rocker spring from a 2.6 valve train for the checking spring. They generally are soft enough.

I expect I would set your engine up with the drivers side advanced a degree or so and the passenger side 3 or 4 degrees up. Once you check the drivers cam and if it is close to what you want make sure the water pump is pushed down as low as it goes since that will advance the other side. You can elongate the WP bolt holes to dial in the passenger side cam.
Now are you going for the factory specs or do you want to move the torque band a little by rolling the cams one way or the other. Hard to do without a dyno though.