Agoda/Booking.com on Mobile

On Mobile, when trying to get cashback on these sites, it creates a "browser" within the Rakuten app rather than directly launching the Agoda/Booking.com app.

As a result, it's extremely tedious to try and make a reservation. While apps like Samsung wallet offer cashback and launches the app.

1. Can I use the Official Booking.com/Agoda app, complete the entire reservation EXCEPT checkout (search for properties, add to cart) - then load the Rakuten app, and finish the checkout process with the stay already logged into my cart?

2. Do you still get cashback for "Pay at property" reservations ? Search function says yes, but I'm looking to double check.

Thanks