The previous RSS3 Protocol version stopped at v0.4.0-rc.1, as the Core Devs wanted to spend more time shaping it and testing it with different solutions.
As the UMS has been stable for over 1 year, and we are also entering a new era of decentralized governance for the RSS3 Network, I think it is time for the UMS to become the next version of the RSS3 Protocol.
The largest advantage is improved interoperability through standardization, everything is standardized and structured. If we want mass adoption, we need it to encourage more developers to build more products and services to attract and serve users.
I cannot think of any risks specifically applied to the Protocol itself. There are general risks, such as flexibility, extensibility etc., that is why we open source everything when it comes to implementation, and let the Community decide what to change in the future.