Hi there. I am the creator of Maple which is a fine-grained reactive web ui library in Rust and running in WASM. We would like to support SSR as a first-class citizen. There are however, a few questions related to design that are unanswered. Even if you have never used Maple before, I would love to hear your feedback about potential ergonomics around the proposed API.
Please visit this issue for more information: Support for static rendering · Issue #47 · lukechu10/maple · GitHub
So first of all, doing this with feature flags may be a bad idea, as this can cause compilation conflicts between crates that have you as a dependency. Users with those dependencies that depend on you in turn may end up with issues like this one. (has this been fixed yet?)
Is this something you can implement, as you say, generically using traits? That would make it far easier to support other backends in the future, as well as allow users to implement their own backends.
The problem I am facing here is using traits: users will have to make all their components generic over the backend which is arguably lot less ergonomic.