Consider: an A2 stock on an AR-15 has a LOP of 13.5”, and almost all shooters benefit from having a cantilevered optic mount which sets the adjustment body at the front of the receiver - a position not attainable with standard vertical rings. Even with my VERY short neck, I still end up with my scopes in cantilever mounts to get my optics forward far enough. Can’t come remotely close to getting my nose to the charging handle unless I’m holding only the toe in the pocket ala Service Rifle Standing, but I still have to push my optics all the way to the front, like everyone else.

Very few gunshops remain in the US which have any experience at all in stock-fitting. We’ve seen far too many generations of generic rifle fitting for any of that to carry forward. Unless a shop has a staff gunsmith who can actually manage smithing tasks, instead of only simple clean and repair jobs, most shops would be a dead end.

The OP is likely to get closer by simply measuring from the crook of the elbow to the tip of the finger. Hold the pad of the trigger finger perpendicular to the forearm bones. Hold the wrist slightly indexed outward, heel of hand SLIGHTLY pressed inward, with the hand tilted downward to between 30-45 degrees (thumb side tilted forward, pinky side tilted backward/downward). Hold the elbow at 90 degrees. Measure between the crook of the elbow and the pad of the trigger finger. This is USUALLY within +/-1/4-1/2” of a natural, controllable, and comfortable LOP for most shooters. This same position can also be used to measure a shooters appropriate trigger reach in the hand.

Bending the frame of your truck to correct poor wheel alignment might be a solution for uneven tire wear, but not all solutions are good solutions.