Process crackers, pecans and coconut in a food processor until finely chopped.
Add butter and brown sugar; process until well combined. Press mixture firmly onto bottom and sides of 9-inch springform pan.
Chill until ready to use.
Sprinkle gelatin over water in a large bowl; set aside.
Cook blueberries, sugar, butter, lemon zest, lemon juice and salt in a large sauce pan over medium heat until blueberries are really soft, about 10-12 minutes.
Using hand blender, puree blueberry mixture.
Meanwhile, whisk together eggs, egg yolks and cornstarch until combined.
Remove blueberry mixture from heat; slowly add 0.5 cup blueberry mixture to egg mixture while constantly whisking.
Return tempered egg mixture, constantly whisking, to mixture in saucepan.
Cook, whisking constantly, over medium heat until mixture is thickened and bubbles, about 1 minute.
Pour mixture through fine-mesh strainer set over gelatin mixture. Discard solids; stir blueberry mixture until gelatin is dissolved.
Let sit, stirring occasionally, until reaches room temperature, 30 minutes to 1 hour.
Whip heavy cream until soft peaks form. Add one-third of whipped cream to blueberry mixture; gently whisk until mixture is lightened.
Using spatula, fold in remaining cream until well combined. Pour filling over prepared crust.
Place chocolate in a medium bowl; bring 3/4 cup heavy cream to simmer; pour over chocolate and stir until smooth. Whip remaining cream until soft peaks form.
Fold in one-third whipped cream to chocolate mixture; whisk to combine.
Fold in remaining cream until homogenous. Spread on top of blueberry filling.
Chill pie for at least 5 hours or up to 24 hours. Run thin knife around edge before releasing the ring.