I think with wins over Oliveira, Volk x2, Poirier, and Tsarukyan he'd be totally qualified to go for double champ. And I hate the whole double champ frenzy with guys calling for double champ before even winning their first belt, but Islam is that elite so it's legitimate. P4P #1 with 4 defenses and having beat all viable challengers is totally good to try for double gold