• Do c/selfhosted members run the *arr stack? Yes, probably the vast majority of them.
• Does OP have a product that integrates with the *arr stack? Yes.
• Is OP asking you to buy his product. No. He's asking you, if you are interested, to beta test a product, and in the end your reward is to keep the product you helped beta test.

This is not an outlandish or usual scenario.