I'm not super happy with this preference at the moment -- it's basically just a flag for whether the last-used filter is 'no filter' vs. the top of the MRU list.  But I was thinking forward to when we might have [saved, named filters](https://trello.com/c/4EQI1XwC/1137-2s-save-edit-multiple-different-file-exclusion-sets), in which case this could have other values.  I could still be persuaded to make it a simpler flag for now, though...