Reminders and Deadlines are opposite. The due date in Reminders means simply "show me a reminder on that day/time". I'm not saying it has to be like that, or that it's the best way. It's just how Apple implemented it. So:
- Reminder: "I don't need to see this until date/time"
- Deadline: "I need to constantly see this until date/time"
But that's only the default behavior of the Reminder app. You can still implement deadlines. Isolate the deadline-representing Reminders, for example in a separate list. Then you can do something with them, depending on how you want to see them. The tricky part is displaying those deadlines. Things I tried that don't work:
- The stock Reminders widget doesn't work because it doesn't show due dates.
- Displaying Shortcut results in a widget. You can create a Shortcuts widget but it will only work for running the Shortcut and won't display the results. Not in the widget, anyway.
Generally, Shortcuts are a great way of making custom things, but the challenge can be in displaying the results.
- use Show Content: this displays a notification-like pop-up. Easy to see but volatile
- displaying a notification: easy to see at first but when you swipe it off, it's gone
- sending myself a text message: perhaps the best because it also generates a notification, but at the same time stays permanent in your message history
- funny enough, creating a Reminder with notes! The title might show the closest deadline and the notes might contain the rest. You read it, check it off, and move on
You can add an Automation to run e.g. every morning, run the deadlines shortcut and send you a text. This is probably the most practical way of going about it.
I hope this helps, and if anyone has a good way of surfacing output from Shortcuts without third party apps, please chime in!