Pass metadata to triggered pipelines with pure YAML

Features Requests
2

+1 to this - we have a lot of pipelines which trigger other pipelines with dynamic metadata.

e.g:

steps:
  - command: "create_deployment.sh" # sets deployment-name metadata

  - wait: ~

  # script which reads metadata + uploads trigger step below
  - command: "profile_deployment.sh" 

  - trigger: "deployment-profiling"
    build:
       meta_data:
          # has to be resolved by script, doesnt work in steps.yaml
          deployment-name: $(buildkite-agent meta-data get deployment-name)

It would be ideal if we could remove the profile_deployment.sh script and just directly put that trigger step into the yaml