If I was going to add an award, and I am not since I don't work there, it would be this.
I would include a separate stat for each player. Favor earned playing solo.
The event would keep track of any favor you would have normally earned via your solo runs only and if you earn enough,
you would be awarded a cosmetic 'lone' wolf pet. At the higher end, you can earn a worg mount to ride.
This award would be the same each season for that stat. No added bonus for qualifying more than once.
That would be it.