Nice setup. We have a comparable setup in our agency developing webapps, apps, platforms and so on.
For each project we use
Board 1: Sprint backlog (SB)
Groups: Develop, Staging, Accept, Production
Board 2: Product backlog (PB)
Groups: Next up, New items, Backlog
Board 3: Epic and User Stories (EUS)
Subitems: User Stories
Board 4: Sitelist / Sitemap board (SSB)
Groups: Webpages, Elements / components
Items: Pages or elements / components
Board 5: Product roadmap
Groups: Planning, Milestones, vacations etc
Items: Deadlines, Milestones, Meetings, vacations etc
Now we are using the Link to item column to link from our SP and PB to connect them to the items and Epics on the Sitelist and Epics and User Storie boards. This gives the tasks on our PB and SP an ‘category’ and with that sorting capabilities.
In our work process we have refinement sessions to prepare our upcoming sprint. The refinement is being done from our Epics and User Stories and Sitelist board on epics, user stories and components. With the feature Two-way linked with 'Link To Item' column (potential subtask solution) it would be doable to refine straight from the Epic board and the Sitelist adding the tasks straight into the PD board. This would be great, but untill that time we are working by creating first our epcis and elements, afterwards connecting the tasks from the PB.
What do you think? Will this setup work for you?
P.s. to limit the amount of boards we are considering combining the PB and the SP board into one. This could be done with the filters on the view switcher in the left corner of a board. Combining the boards has pros and cons, so not sure yet.