Make the shortcakes: Line a baking sheet with parchment paper. Pulse the flour, sugar, baking powder and salt in a food processor until combined. Add the butter; pulse a few times until the mixture resembles coarse meal. Add the heavy cream and vanilla; pulse until the dough just starts to come together. Turn out onto a lightly floured surface; gently pat into a 5-by-7 1/2-inch rectangle.
Cut out 6 rounds with a 2 1/2-inch-round cutter; place about 2 inches apart on the prepared baking sheet and refrigerate 30 minutes. Preheat the oven to 350 degrees F. Lightly brush the shortcake tops with heavy cream, then sprinkle with sugar and the coconut chips. Bake until golden and the coconut is lightly browned, 17 to 20 minutes. Transfer to a rack to cool.
Meanwhile, make the blueberry mixture: Toss the blueberries with the sugar, lime juice and salt in a large bowl. Let sit until juicy, at least 30 minutes.
Just before serving, make the whipped cream: Beat the heavy cream and vanilla in a large bowl with a mixer on medium-high speed just until stiff peaks form, about 2 minutes. Gently fold in the coconut cream and lime zest until just incorporated. (Do not overstir or the mixture will become too loose.)
Split the shortcakes. Stir the mint into the blueberry mixture and spoon onto the shortcake bottoms. Top with the whipped cream, then the shortcake tops.