To be able to assign Checklist items (and so that users know what Cards they should attend to) I have to add them as a Member.
But if there are several Members on a Card, there is often a Diffusion Of Responsibility And, in particular, if that Card's progress is "waiting" on someone, then it's unclear to that person that they are the "holdup".
SOLUTIONS 1. Being able to tag someone so they see you are the "next action" (the holdup) on this Card 2. Assign someone to be responsible for moving that Card forward. Then that owner would look at the card and see that it's waiting on "Bob" and notify Bob (and flag the card "waiting on".
But I see no way to do either of these.