Just use JSON for everything that is supposed to accept YAML, and rely on the fact that the entirety of JSON is somehow a subset of YAML and that most YAML never actually needs the "features" of YAML.

At least with JSON, tooling can help you find invalid syntax in the middle of your file.

And JSON tooling/libraries (compared to YAML tooling/libraries) are usually faster, easier to use, have less bugs and present less incompatibilities between themselves most of the time.