Hey HN, we're building a similar product at https://evertrove.co -- we don't have the limits Kendra currently has, and integrate with a lot more services. We're still early and figuring out what the pricing structure should be, but we're making it a lot more competitive than Kendra is.
We'd love to talk to you if you're interested in using Kendra. We're also wondering if there's more value on the Question Answering side of things, or the document retrieval side of things? Would love your thoughts!