Rather than a straight delay, add a node in Workflows that "waits until" a user has triggered an event (or other action).
In a workflow it would be useful to add a logic node/step that that lets you hold the customer at any point in the journey until an event is triggered or until a specific time is reached.
Looks like this has already been added - https://getvero.canny.io/feature-requests/p/add-a-wait-until-node-in-workflows
@David Crowther: Thanks for pointing that out! :) I will merge this one into the existing request.