30 mm nylon standoffs have been used for rising the FC shield and providing enough save for the receiver to also be attached below the top plate. 20 mm standoffs would have been enough without the receiver with pin headers still pointing up.

The positive (+) wire from ESCs to FC is only connected from ESC of motor 1. The positive (+) pin header on the FC isn't in place for motors 2-4.

Few grams of weight could have been saved by reducing the length of signal wire from ESCs to FC.

HobbyKing 6A ESCs were replaced with Favorite LittleBee 20A ESCs in order to gain damped light (break) support, 20A is overkill in this use but the size of these ESCs are close to same.

The receiver was moved below the FC which resulted in a cleaner looking build.

This setup doesn't need a BEC as both receiver and FC are 2S compatible.

Favorite LittleBee 20A ESCs had to be removed as those were unable to provide reliable acceleration with the T-Motor MT1306 3100KV motors regardless of used BLHeli settings or version. (up to version 14.3 tested) See https://www.youtube.com/watch?v=fBt-Bm7Ky_s