Hi Robert,
The default you are asking about is system wide, so (statistically speaking) is best set to whatever benefits the majority.
For the exceptions, consider creating and using a Template with "the opposite" setting on its Tasks, and training people to copy an existing task within a Project (thereby getting the same such settings) rather than inserting new Task (which will get the "wrong" defaults and require additional editing.
Finally, whether in Legacy Gantt or List View, I'd encourage you to keep the Task Constraint visible so it can be easily reviewed and corrected as needed.
Regards,
Doug