Follow-up on 2.8.2.4:

Next to Reminders, I also have to create Calendar events for Things to-dos. Having the next action creation automated, makes using Things as an idea manager easier.

When I run the New Next Action shortcut on the selected to-do, Shortcuts ask me if I want to create a new reminder or a new event. Events are created for the next day, then revealed in the Calendar, so I can continue to edit them.