Multi-map linking and entities for very complex work

As our SaaS platform product grows in breadth and complexity, it gets harder to manage on one board. A high-level product (or even feature) board could easily contain a card that decomposes into an entire “step” or “journey” card or even an entire board.

It would be nice to be able to “drill down” link a card on one board to a “step” card, “journey card” or an entire board.

The “rollup” card should aggregate total story points (requested/delivered), and maybe show other details such as number of journeys, steps, cards in the drilldown view (less useful but could have value).