So lobby those projects to add more support. Heck, make a PR to add the serialization language of your choice. Start coding. If they don't want patches for "[insert data serialization formation here]", maintain your own fork.

FWIW CloudFormation added YAML, which was a vast improvement to usability IMO over where they started. Want CloudFormation to support something else? Lobby through your AWS account rep for what you want supported.