React has shipped experimental support for custom elements
github.com
github.com
Key point:
> The behavior has landed in the @experimental builds, but we haven't yet reached a final decision on the behavior for the 18 release. You can start using it right away in the @experimental channel, but whether it lands in @18 or gets deferred to another major release depends on the amount of real-world testing the @experimental build will receive from the community. If we can get apps using WCs widely try it in practice in the new few weeks and provide feedback on the new behavior in the @experimental build, we might be able to include it in 18. If we don't get enough feedback by that point, we might have to keep it @experimental-only until we have more confidence that the new behavior doesn't have big flaws.
[0] https://github.com/facebook/react/issues/11347#issuecomment-...