It turns out the “decluttering-card” available in HACS does exactly what I wanted. Yea! Custom cards for the win.
That said, I do still see the benefit in what was described in this thread. In a previous iteration, I created a blueprint (well, I modified someone else’s blueprint) to create schedules for multiple devices, but I had to separately create datetime helpers and boolean helpers for each instance of the blueprint. It would have been great if they all could have been defined in one place, including the card to show them in Lovelace.