Non English publication would be fine. Its the review process that matters. I have no problems believing that a colloquial form of Sanskrit was spoken, that wo

Non English publication would be fine. Its the review process that matters. I have no problems believing that a colloquial form of Sanskrit was spoken, that would be the very definition of a vernacular. A situation not different from the Latin example you gave. Records of a direct quote of a protagonist who is commoner, in literature or preferably in royal records etc would be acceptable evidence. Otherwise how can one differentiate it from claims that humans rode dinosaurs with wings. BTW I don't disagree with you when you state there is a bias against such subject matter (you can look up the issue of Taylor's expansion of trigonometric functions by the Kerala school of mathematicians much before Newton). The way to address this would be do counter that with proper research results and processes.