I have two samples of full ancestry from West Bengal. A Kayastha and a Brahmin. You can see where they plot.
Bengali Brahmins are very similar to North Indian Brahmins (often they have some “eastward” shift). In contrast, the Kayastha individual looks like the Bangladeshi samples, except with far less East Asian ancestry.
I do want more samples. Though I’ve gotten a few Bengali Brahmins and they exhibit the sample pattern as above. I am curious about non-Brahmin West Bengalis. But from the above, I think I will conclude that the hypothesis that Kayasthas are a cultivator caste which uplifted themselves occupationally is probably the right one.