Only happens at 9.9/10ths of maximum cornering grip so pretty much never a concern on the street, as far as I can tell.
I never could understand why people talk about understeer on the street?
Different story on the track . . . gotta have all 4 tires howling pretty good before any significant understeer shows itself . . . I just can't imagine doing that on the street.
Ideally one should have matching tires all around but if circumstances prevent that from happening I don't think there is going to be an issue in most cases.