If Simon can find time, here are my own "favourite" ideas to go further.
- (small matter) Highlight the column header row.
- Applying or removing filters often destroys the current column width settings. Can they always be preserved?
- It seems that clicking any of the top 4 checkboxes ("Enable" or against any target column selector) refreshes the grid content. Can this be disabled until "Apply" is clicked?
- It seems that the filters operate as "contains" any character or string in the text box (sometimes not adequate). Could we have the option of "initial match"?
- Add a new frequency filter option, pre-filled with current frequency, plus user-supplied "tolerance".
- Drag any column to a new position.
- Add a dialogue similar to Filter, with multi-column sort and individual Asc/Desc.
(To cope with a possibly frequent initial sort by frequency, with or without Source, at least 5 levels would be preferred.)