Do the JRA’s limits on revocation authority apply to unsupervised cases?

Yes. In general, except where the statutes say otherwise, an unsupervised probationer is subject to the same rules as a supervised probationer. G.S. 15A-1341(b). The limit on a judge’s authority to revoke is set out in G.S. 15A-1344(a), which is not restricted to supervised probationers. There is some argument that the reference in G.S. 15A-1344(d2) to defendants “under supervision” for felonies or misdemeanors was meant to limit the confinement in response to violation law to supervised probationers. But that reading is hard to square with G.S. 15A-1344(a), and it would be counterintuitive for the JRA to allow revocation for unsupervised probationers and not allow it for supervised probationers.