Is it even wear? In other words, no feathering or cupping?
Inside wear is generally from too much negative camber or toe-in. At your next alignment, you can request either or both to be adjusted closer to zero, but within tolerance.
As alignment shop stated, rotating side to side helps. But you can't just swap wheels side to side because of the directional tread pattern. You would have to have them dismounted and mounted.
300 treadwear rating for a tire of that type is pretty good, so improving on that will be slim pickings.