The guys who are winning $10,000 in this sport are not using LR wheel for stagger changes, there is so much more happening. Stagger changes are accomplished by growing or shrinking a tire, LR wheel width changes how a kart rotates, unloads and loads the LR.
You can use it most likely you had 8.25 " and now got 8.5 " the off set in the rear is different, measure from bearing hanger to the wheel with your normal left rear on then put your new wheel on and just move the hub out to the same measurement, which you will move the hub 1/2" , and yes be aware of your stagger difference.
On our 09 Icon moving the left rear out makes the rear loose on some tracks with 8.5 wheel. Slide it in with 8.25 wheel and it is perfect throughout the turn.
In general yes, however by positioning the inside of the wheel the same you can kinda look at it like your not moving it, the added stagger would most likely make more difference than just the wheel being moved.
More often than not people move the LR to adjust for what they feel will help something on corner exit. In reality, moving the LR changes the timing of when it unloads on corner entry before it can have an affect on the timing of it reloading on corner exit. Entry comes before exit.....