► Slice 2 limes into medallions, as thin as possible, horizontally through the center.
► In a wide, shallow pan over medium heat, heat sugar and water, stirring occasionally until sugar completely dissolves. Reduce heat to medium-low, so it maintains a simmer, and add lime slices. Simmer for 30 minutes, stirring and flipping slices occasionally.
► Once done, place caramelized lime slices on a baking sheet lined with parchment paper. Heat oven to 200°F. (Alternatively, if you wish to serve mousse the following day, you can let lime slices dry overnight. If choosing this option, skip the next step.)
► Bake lime slices for 1 hour (with convection if you have it), flipping every 15 minutes.
► Combine cream and honey and whip until stiff peaks form. Separate ¾ of the mixture and set aside. Zest remaining lime and set aside.
► Crumble cheese into ¼ cream mixture and beat until soft and creamy. Fold in remaining cream mixture along with most of the lime zest, saving some for finishing. Using a piping bag (or plastic bag with a snipped corner), pipe mousse into small jars or bowls, cover, and chill for at least 1 hour. When ready to serve, top with flaky salt, reserved lime zest, and caramelized lime slices.