coffeediver,

You don't have enough wear on that trigger to cause what you are experiencing.
I have the same rifle in .308 and have over 4300 rounds through it in the Accu-Stock.
I adjusted my trigger to 2 lbs. as soon as I got it. At about 2500 rounds, the rear spring loosened up to under 1.5 lbs and I experienced the front tab lock-up that comes from having the trigger set too light.
I readjusted it and put a drop of Locktite on the adjustment screw and it hasn't happened since.

I have an earlier 10 FP .308 with a hidden mag and have over 10,000 rounds on its trigger. It has a hidden mag and an upper bolt release. It is also adjusted to 2 lbs but the spring never loosen and has been functioning flawlessly since 2009.

I have 9 Savages, and have two with top bolt releases mounted in Oryx chassis. Never had to move any springs to get them to fit perfectly. Never had the trigger issues you had either.
As I understand it, the Oryx chassis has a slot to allow you to release the bolt.
Perhaps that is the issue. I have never tried to mount the Oryx on an lower bolt release, so I can't comment on whether the lower bolt release might be the problem.