Fields are usable today in more than just ticket views - they can be used as filter and sort criteria both in the left-hand pane and within the main ticket list window. We would like to be able to either:

a) Choose whether a field can be included in sort criteria.
b) Have a better way to choose criteria in the 'Order by' and 'Group by' functions.

When the amount of fields grows, the 'Order' and 'Group' dropdown becomes unwieldy. Being able to choose which fields can be used would be nice, but perhaps a better interface for that dropdown would be easier, such as having a text entry box that can be used to filter the fields instead of showing them all in one continuous dropdown.