Could you please explain in detail what did/didn’t work in the beta version? Do you have a test-environment on which I can perform some tests?
It’s true that ‘Update Cart’ must be clicked before it’s actually added to the cart; same as changing the amount of items in the cart. This is the way WooCommerce handles the cart. I might add a solution for this in the future, but it’s not planned yet.
The previous version had 1 notice which might have caused issues on your site. I sent you an updated version, please let me know if that one works. If it doesn’t work please provide me as much details as possible.