I have a Strat, and a Les Paul. Profiles that sound best for my Strat don't work as well for my LP, ect... If I had a Custom Field to sort by (like Favorites or Last Imported), I could add one called "Strat" and another called "Les Paul". That way, when I plug in my Strat, I can sort to the "Strat" profiles. When I plug in my Les Paul, I could sort to "Les Paul". With so many profiles, it's hard to keep track of them all!
The custom sort field idea works for types of music too. For example, "Blues" or "Metal". Sorting by "Metal" would bring up any profiles I have specified for that genre.
This is a great way to make the hundreds of profiles work more efficiently.