Or are any In-Q flows that you create applied to all call flows?  That doesn't seem right but I don't see a way in Architect to specify how/where the In-Q flow is applied. Do you drag and drop the In-Q flow into another task?

You should be able to use the Transfer to ACD action and specify an in-queue flow when you click on "Override default in-queue handling". See if this helps: https://help.mypurecloud.com/articles/set-up-a-transfer-to-acd-action/