The default preset is the one that appears first in the Presets drop-down list, knowing that the list is sorted by category, and then alphabetically within each category. So if you have the following presets available to the File Sequence export:
The default preset for File Sequence is Alias for grading. A new preset named DPX for grading in the Project section will become the new default for File Sequence. The same preset but in the Shared section means that Alias for grading remains the default for File Sequence.
You can have one default preset per Export Type.
To set a default format preset:
You will create a renamed copy of this preset in the step below.
This creates a renamed copy of the preset. Make sure it name and category makes it appear at the top of the Format Preset drop-down list.
You have just renamed the original preset and copied it to the Shared or Project section.