Conceptually speaking I believe mestizaje is exceptionally weak in describing any shared cultural identity. At most it is useful in the same classifying sense as the casta paintings are. Otherwise mestizaje has been an ongoing site of assimilation and colonial imposition. Going as far back as Jose Vasconcellos his theory of a cosmic race is eugenics in disguise and is written from a eurocentric position in which it is okay to give up indigenous cultures in order to merge them with eurocentric ideals. The concept of indigenismo also emerges from the same groups in Mexico, wherein the national identity of Mexico was constructed cherry picking indigenous leaders, and historical moments to add to a newer narrative of Mexican history. Essentially this process absolves colonizers and eurodescendents from the guilt of colonialism as the national identity becomes shared amongst all citizens. The struggles of indigenous people in LA are often taken less seriously as the state views most of the citizens to have some indigenous blood. Meanwhile indigenous groups face problems unique to them and are often dismissed by the non-indigenous mestizo who claim to share in their identity given the past. To me personally mestizaje shares very similar flaws with latinidad or a shared latin american identity.