In kubernetes transformers, the following sample uses appName and serviceAccountName as arugments which will eventually be part of the component model and these names can not be used across any other transformer.

https://github.com/devopzilla/guku-devx/blob/5743b77354638b7fe4e592ddaf83df47e6691a19/pkg/guku.io/devx/v1/transformers/kubernetes/transformers.cue#L35-L36

As a suggestion, I would add some annotations field to $metadata and use it as a freemap then use it to define arguments, for example:

#SomeTransformer: v1.#Transformer & {
  v1.#Component
  …
  $metadata: annotations: kubernetes: deployment: appName: string | *$metadata.id 
}