Protecting a microcontroller powered from a 1500W 12V supply
Build your controller.

Check for shorts with an Ohmmeter before you connect to a power supply.

Test with lower powered supply (same voltage, less current) and fuse protected.

When all tests show the controller is OK, install it on the copter. Treat the controller as a sealed unit.  Any change means you take it out of the copter, and repeat the low power tests.

This should catch any assembly errors.

If you can strap the copter down, you can run full power tests on the ground with fuses in appropriate places.  When the full power tests run through with out shorting out, you can let the copter take to the air.

You really don't want to catch assembly errors with your expensive toy 50 feet up in the air.  Find them on the ground, fix them, then take to the air.