Email Automations based on Shifts/Shift Tags

It would be helpful to be able to schedule email automations at the shift level instead of the opportunity level. Some of our volunteer shifts within an opportunity require different information to be shared with the volunteers depending on their role or the venue location but we don't want to create a new opportunity for them. We use tags for all of our shifts so if the function was available, we could set up automations based on shift tags instead of volunteer tags.