In current generative terms, individual features trigger small-scale micro and nano-level differences among mutually intelligible varieties with shared geography (cf. Barbiers 2009, Kayne 2000, 2013). However, as we show in this paper, dialects may also exhibit macro-level differences such as in the domain of case alignment. Specifically, we employ novel data on ergativity from Braj, a Western Indo-Aryan language, to present two such instances. First, despite a rigid ergative system in the transitive domain, some Braj varieties have undergone a macro-level change in the unergative domain by opting for phi-triggering, unmarked/nominative subjects. Another instance of a macro-level difference is provided by the duality of grammars within two registers of the same Braj variety. The occurrence of such macro-level differences at the dialectal level is unexplained in the literature, which advocates a complete separation of big, structural differences from featural variation (Baker 2008). Our submission is that structural differences also define dialects and registers, though they are mostly restricted to specific domains, unlike those found in typologically distinct languages with typical cascading effects.