I see dual jacks only rarely - but I carry a 2-to-1 adapter, just in case. These days if the seat has dual jacks there are almost always fairly good free headsets; my carryon has a collection of them. Still, I prefer my over-the-ear Senn PX550 noise cancelling headphones - I wear them even when all I want is quiet. They are BT to my phone and laptop, but wired to the IFE. Looking forward to using them completely wireless. Every 20th flight I leave the ]{}}#%^ cable plugged in. Cables are cheap and Amazon can sometime deliver to my destination hotel before I get there.