> not far fetched to imagine Indians speaking Sanskrit and Prakrits fluently and switching them based on context.
Any evidence in the form of records that this indeed happened. You are promoting a nonstandard position, so the burden of proof will be on you.
> historical changes in Sanskrit used in the Vedas.
This is just one small corpus of Sanskrit linguistic traditions. It hardly gives them expertise over the rest of the traditions spanning few millennia.
Jains, Buddhists and various other Sramana movements were championed by lower varnas and they all used Sanskrit as a liturgical language.
I have already mentioned the widespread presence of edicts, danapatra, inscriptions, secular literature created for wider public which hints that Sanskrit was widely understood and Sanskrit/Prakrit Diglossia is not too far fetched.
That was just what her dissertation was on, not the sum total of her expertise. I was responding to your question about familiarity with history in addition to linguistics of Sanskrit. In any case it's expert vetted piece of research, not claims about far-fetchednesd by someone on the internet.
Far fetchedness is hardly the the standard for wannabe scientific claims. If it was, there are many bridges that people can sell.
If proof free speculations are your thing, speculate away. There's a large population of similar proof-free quacks and hacks one can join. I have nothing more to add.
Funnily enough I’ve given enough examples and sources already in this thread. I think it’s better than “I know someone who knows” and “it’s expert vetted research”. I’ll stick to my theory about Sanskrit/Prakrit diglossia for now.
In the end we are two lay people arguing about a topic we’re not experts in and speculating how things would have been few millennia ago. It’s fine to have diverse perspectives! I’m not sure which quacks you deal with but I wish you all the best.
आ नो भद्राः क्रतवो यन्तु विश्वतः