Not actually an issue, but an enhancement which I could need, an which - if wanted - I could provide an PR for:
I would add an Option --includeScopeId which allows to export e.g. only the config data for website number 42 by typing
bin/magento c:d:e --includeScope=websites --includeScopeId=42
Would that make sense in your eyes?
Best regards,
Willi