Basically prefix the order string with something like zzz-
. It pops up in quite a few dialogs and searching makes it easy to pick one of the recipe signal instead of what you actually wanted. Having it as the last category would mean it would only jump into there if it could find nothing in the other categories.
Picture of what currently happens and how it can cause problems: https://i.imgur.com/vb79IzO.png Factory Search is only one example. We also have it happen regularly with constant combinators that should send an item signal.