I incorrectly posted this in the suspension forum but intended to put it here. Any insight is appreciated.

In February of this year I replaced the Continental ContiProContacts with Continental DWS06 tires. I have had issues getting these tires to balance properly as the car has exhibited some vibrations. The front and rear suspensions were professionally replaced in May of this year. The tires were installed by my local Firestone store on my 2002 BMW 530i. The car had 100,000 miles when the tires were installed.

Fast forward a few months and I have had the tires re-balanced a few times. A few weeks ago my Firestone store directed me to one of their other stores that has a Road Force machine. I have lifetime rotation and balance on these tires so this was covered under their warranty. I took the car to the other store and the results are below:

Left Front - 1 Lb road force (my understanding this is good)
Right Front - 10 Lbs road force (not sure if this is good or bad)
Left Rear - 21 Lbs road force (my understanding is this is bad)
Right Rear - 13 Lbs road force (not sure if this is good or bad)
I was told the wheels are true.

The tech adjusted the left rear by marking and deflating the tire in addition to marking the wheel, breaking the bead/seal and rotating the tire on the wheel to minimize the road force. After this process the measured road force went down from 21 Lbs to 6 Lbs. This has improved the vibrations but I still get some vibrations at highway speeds, although it is intermittent and borderline tolerable.

Question is would it be beneficial for me to have the two that measure 10 and 13 Lbs road force broken down and rotated in this same fashion. I would like to get the road force in these two tires as low as possible, but am unsure if it is worth the effort to work on these two. Is 10 and 13 Lbs road force enough to notice (I think so)? Any insight or recommendations from the experts on whether this would be worthwhile?

Thanks!!!