meta_query with standard getEntityRecords possible?

As far as I can tell, that’s still not possible. getEntityRecords() uses the REST API, but that doesn’t support meta queries by default. You can follow ticket #47194 if you’d like to keep tabs on the request to add support, or contribute to it.

For now, using rest_{posttype}_query seems to be the conventional way to achieve what you want. I’d recommend that over creating a custom endpoint.

Don’t forget that you’ll need to register the meta if you also want to see it in the response.

tech