Hi, I see some design flws in your construction.
The electronics boards must be always underplated with some insulation layer that in case of crash can prevent to burn down of the whole copter. I use for example 2 types depends on the size of copter.
- CNC machined laminated board o glasstextit board.
- 3D printed PLA plate or board underneath the electronics.
Maybe it few grams extraweight but definitely save your electronics. Also the design is very important to have maximum strenght at the center plane of the copter to get electronics protected
Keep safe flying