Animate Editing Mode

Each canvas is either in Animate Editing Mode or it isn't.

When in Animate Editing Mode, each time you edit a parameter (whether directly in the params dialog or indirectly by moving a duck), a waypoint is created to remember the change, and the position on the timetrack at which the change happened.

When not in Animate Editing Mode, changes to a parameter will be applied throughout the entire timeline of the animation. If there are already waypoints on the timetrack for the parameter in question, this causes an error and your edit will be disallowed.