As an administrator of a large instance, I'd like to control the threshold for the Custom Field Optimizer

As per this documentation the custom field optimizer will show custom fields that have a global context, but are used in less than 10 of all projects.

In very large instances (the size that this tool is aimed to help) it's conceivable that 10 might be too low a cutoff point.

It would be good for system administrators to be able to adjust the cutoff point (either as a value or a percentage, depending on what makes more sense).