I looked into them a while ago, and it looks like the silhouette id slides in the back, behind the dial cardboard itself. It also looks like there will be plenty of ID tokens, no need to worry.
From their product page:
Customize and enhance your maneuver dials as you declare your allegiance to the Galactic Empire with the Imperial Maneuver Dial Upgrade Kit for X-Wing™! This pack includes three detailed plastic protectors for your ships’ maneuver dials. In addition, you’ll find dial ID tokens to easily identify which dials match your ships in the heat of battle. Choose your maneuvers quickly and stylishly with the Imperial Maneuver Dial Upgrade Kit.
https://www.fantasyflightgames.com/en/products/x-wing/products/imperial-maneuver-dial-upgrade-kit/
From the article:
A pack of maneuver dials includes three dial ID tokens for every ship from the T-65 X-wing and TIE Fighter in the original X-Wing Core Set, up to the T-70 X-wing and TIE/fo fighter from Star Wars: The Force Awakens™ Core Set! Soon, every X-Wing expansion will include a dial ID token for you to use with your plastic maneuver dials if you so choose. These will begin with the Ghost Expansion Pack, the Mist Hunter Expansion Pack, the Punishing One Expansion Pack, and the Inquisitor’s TIE Expansion Pack. Standard cardboard maneuver dials will still be included in each expansion.
https://www.fantasyflightgames.com/en/news/2015/10/22/ace-maneuvers/
So one pack will cover most 3 ship lists, 2 packs for larger lists, and 3 packs for swarms. I am actually looking forward to these, as storing 3 or more of these and then being able to get rid of half of every dial I already have will actually save space in my case. Beside that, I think they're classy. I might even paint some kind of scheme on mine to personalize them even more.
How will they save space as they are slightly wider AND thicker???