Preheat your oven to 400°F.
Stir together both types of coconut milk and the vinegar in a small bowl and set aside.
Use the grater insert for your food processor to shred the vegan parmesan, then mix it with the vegan cheddar shreds in a bowl and set aside.
Place the first 7 ingredients in a food processor and pulse a few times to mix.
Add half of the cheese mix to the food processor and pulse several times more.
Put the frozen margarine in the food processor and pulse a few times until the chunks are roughly pea-sized.
Dump the contents of the food processor into a large mixing bowl and toss the rest of the cheese and the chives in with the flour mixture.
Stir 3/4 of the liquid into your dry ingredients until combined. Add the rest a few teaspoons at a time until it comes together as a dough. You may need to use your hands at the end to get everything mixed in. It should form a slightly sticky (but not ‘wet’) dough.
Rest the dough in the fridge for 10 minutes, then dump it onto a counter or parchment paper lightly dusted with tapioca starch and gently pat until it is about 1 to 1 1/2 inches thick. Using a 3-4 inch round cutter, cut the scones and carefully transfer those onto parchment-lined baking sheets. Alternatively, pat into two 8-9 inch circles. Cut each circle into 8 triangles. Pop into the freezer to chill for another 5 minutes.
In a small bowl stir together the melted butter, sugar, and salt and set aside while the scones chill.
Brush the scones with the butter mixture then bake for 18-20 minutes, rotating halfway through baking time.
Allow the scones to cool on the pan for 5 minutes, then remove to a wire rack to finish cooling.