I'm an Indian Atheist myself, but I never found my move away from Hinduism to be difficult or grating. My parents & community just sort of accepted it and moved on. If I had to be pedantic, I could call myself a Nastik/Charvak Hindu and I would technically be an 'Atheist Hindu'. I did have a "I refuse to do a namaskar or enter temples" Dawkinian emo-phase, but at some point I realized I was fighting against a bogeyman that didn't exist.
My current opinion on the matter, is that Abrahmic conceptions of Atheism do not work in a religion that does not have blasphemy or any single source of truth. So, while a term such as ex-muslim/atheist usually messages a certain ostracization or scientism, being an ex-hindu doesn't immeditely mean anything to me.
To use a favorite HN comment of mine : "If it's hard to tell the difference, it'll be hard to sell the difference".....and I can't tell the difference between a Hindu and an ex-Hindu.
(feel free to ignore it. My comment does seem a little out of place in a festival celebration thread. But, I got curious)