Creating a ria sibling only if store exists

Is there a way of creating a sibling of a given dataset in a ria store but only if that store already exists? I use datalad create-sibling-ria to create both the store and a sibling in the store, but I want a command that attempts to create a sibling in a store and fails if the store doesn’t exist. Is there a way of achieving this?

I don’t think it is possible right now (at least with some built-in convenience), but I filed https://github.com/datalad/datalad/issues/5982