I see that we have many such deployers around and strangely the BeanMetaDataDeployer is considered relevant and the BeanMetaDataDeployer ends up deploying these BMDs. How does that work (since the attachment keys are *not* the type name of the BeanMetadataDeployer's input)? Is there some specific deployer specific config that allows this to work?
The component deployers use DU::getAllMetaData(BMD.class) which checks the actual type of attachment.
Why is relevant? -- there is no reason not to be, for that component deployer -- see KernelDeploymentDeployer