I wanted a sub 250gr AUW, but I had a lot of demands; big motors, digital vtx, beefy frame, and to be able to fly with 850mah batteries to get a minimum of 4 minutes flight time.
You can check out my video about it here;

I did a lot of modding to get it so light, I'll try and sum them up here:
Frame
-cut down the tpu camera holder to save weight
-I've put them on backwards and melted an extra hole to mount the camera as close to the post as possible, and behind the post, so now it sit's further in the frame and is protected by the carbon, I saved about 3gr here.

FC board
-I used the betafpv 2-6S AIO 35A board, mounted on a 3D printed 20x20 to toothpick style adapter ( found on https://tmacfpv.com/fpv-pilots-den/)
-I rotated it 90° clockwise so I had the lipo leads coming out sideways, and easy acces to the usb connector.

Don't forget to correct your fc rotation in Betaflight and remap your motors!

Motors
These are the T-Motor F1507 3800KV motors. They are the lightest motors I found in there size 15XX. They came in at 14.9 to 15gr with the full length motor wire. Check out a mini review here;

Caddx Vista Nebula Pro

• Took of the casing, so it's naked. It's pretty easy to do this, remove the screws and you can take it apart. You wil feel a little resistance this is the thermal paste between the casing and the PCB.
• DO be carefull, there are two boards connected with a ribbon cable, be carefull not to damage the ribbon cable!
• I used nylon spacers to keep the boards apart and nail polished the boards to waterproof it, be carefull not to get any in the ribbon cable connectors!
• The ribbon cable is secured with antenna glue so it doesn't come loose.

Titanium bolts
When I finished my build I ended up with a 250.05gr AUW, which was on the on the limit. I wanted to loose some more weight so I had the option to chose other props or a better antenna.
I ended up replacing all of my bolts with titanium ones, yes this is not cheap (€55) , but for me in this build it was worth it.

My final weight with the lightest props I have ( HQ 3x3x3) : 145.6gr