Just a quick note as we have just spotted an upcomming micro FPV quadcopter from Eachine, that is just 58mm big called the Dust X58. At 35g with battery (25g empty weight) this is definately an interesting little quad. At this size you still get Dshot600 ESC, a F3 flight controller, with the all new ICM20608 IMU connected via SPI for fast update rates! So on paper at least it seems like a very good option.
We will be getting this in to review over on blog.dronetrest.com and if its good we will ofcourse be selling them 
Specifications
Dust X58
Brand name: Eachine
Item name: dustX58 FPV racing drone BNF
Wheelbase: 58mm
Package size: 18316377mm
Weight: 150g (included the package)
Take off weight: 35g
Weight of the drone: 25g (without battery)
Bottom board thickness: 1.5mm
Carbon ring thickness: 2mm
Motor: 0703 20000KV motor
ESC: 4A 1S Blheli_S 4 in 1 ESC D-Shot 600
Propeller: 40mm 3-blade propeller
Camera: 5.8G Wireless Camera with 5.8G 48CH NTSC/PAL video transmitter
Flight controller: F3 Flight Control Board Built-in 8CH SUBS Receiver for X9D Plus
Battery: 1s 450mAh lipo battery
F3 Flight controller:
Size (PCB): 21x21 mm
Weight: 1.4g, 1.7g ( including antenna)
Built-in SUBS Receiver for Frsky X9D Plus
CPU: STM32F3
SPI: ICM-20608-G Accelerometers and Gyroscope
Mounting Hole: 16x16mm, M2
Can support current, voltage monitoring
2.4G Receiver
Channel: 8CH
SUBS Output
Control Range: 200m
4A 1S Blheli_S 4 in 1 ESC D-Shot 600:
Size(PCB): 21x21mm
Mounting Hole: 16x16mm , M2
Weight: 1.35g ( not including cable)
Firmware version: Blheli_S
Input Voltage: 1S
Con.Current: 4A
Peak Current(10s):5A
BEC:NO
Programming: YES
D-shot 600 ready in default
Support D-shot150, D-shot300, Oneshot125 and Multishot
5.8G wireless camera:
Frequency band: 5362-5945MHz
Channel customer: 48
Modulation type: FM
Channel SEL: Touch Switch
Channel Indicate: CH1~CH8 Channel indication with 8LEDS and A~F frequency group Indicate with 6LEDS
Transmit power: 13±1dBm
Frequency control: PLL
All harmonic: Max -50dBm
Frequency Stability: ±100KHz (Typ.)
Frequency precision: ±200KHz (Typ.)
Channel Carrier error: 1dB
Antenna Port: 50 Ω
Input format: NTSC/PAL
SENSOR: PAL:720X540/NTSC:640X480 1/4”
LENS ANGEL: H:120°/V:100°
Base-band interface: (P1.27*2)
Power consumption: 200~215MA@5V DCIN
Supply Voltage: 2.9-5.5v
Operating Temperature: -10℃~+60℃
Profile dimension: 14.5mmX12.2mm+14.5mmX12mm