[Feature Request] Sort charts by difficulty number, ignoring difficulty level

[Pikminiman]

DDR A has a really nice feature that allows players to sort all charts by difficulty, or "Level." Crucially, this differs from sorting by "Expert Meter" or "Hard Meter" because if the user specifies difficulty level 7, then DDR A will show all step-charts with a difficulty of 7, regardless of whether the charts are Easy or Expert level. A similar feature in OutFox -- a sort category for chart-difficulty numbers, ignoring difficulty levels -- would seriously improve usefulness.