Something I found out about that may be of use. Yes Google Pay will not work on beta versions.
In the UK, Samsung Pay is not available with Nat West AND Google Pay isn't available on the Watch. So as an alternative, I've switch over to Samsung Pay and set up Curve. These both work with Nat West, the watch and with the Beta version!! Plus you can add additional cards, choose the cad you want to pay with and add in Loyalty Cards etc.
Note, I don't work for any of these.. Just a useful tip!! 😁
Both Google and Samsung pay will not work as well as for NatWest, this is because the Beta version has security risk attached to it. Once the full version is released all will work as NatWest now support Google pay.