In a medium bowl, pour in the light coconut milk, add the maple syrup and lime zest, then sprinkle in the chia seeds. Use a small whisk to vigorously combine everything until evenly suspended — this helps prevent clumping.
Let the mixture sit at room temperature for 10 minutes, then whisk it again with the back of a spoon to break up any forming lumps.
Cover the bowl and transfer to the refrigerator to thicken. Chill for at least 1 hour (or up to 24 hours) — the longer it rests the thicker and creamier the texture becomes.
While the chia sets, place the chopped mango in a blender and puree until smooth. If the mango is very thick, add 1 tablespoon of the chilled coconut mixture or a teaspoon of water to loosen the purée for a silkier texture.
If your coconut flakes are not already toasted, heat a small dry skillet over medium heat and toast the flakes for 2–3 minutes, stirring constantly, until golden and fragrant. Remove from heat and let cool.
Assemble the puddings in two jars or bowls: start with a couple spoonfuls of mango purée, add a layer of chia pudding, then repeat once more and finish with a small spoonful of mango on top for color.
Sprinkle the toasted coconut flakes over each serving and grate a little extra lime zest on top if you like. Serve immediately or keep refrigerated until ready to eat.