I’ve added switches on the O3 power on all my aircrafts which use the O3. I keep the O3 off until I’m ready to arm.
This is the switch I normally use.
I also use this switch if I want the switch to be even smaller.
In order to increase the current capacity, I short the appropriate pins together in order to turn the DPDT switch into a SPDT switch (I’m not sure this is needed). The DPDT switch is smaller than the SPDT switch mentioned above but the larger SPDT is a little easier to mount.
After soldering the wires to the switch, I add some heat shrink tubing and I also add some Polymorph in order to add taps to the switch. The tabs make the switch easer to mount to my aircraft.
Edit: I orient the switch so the forward movement of the aircraft “blows” the switch towards the on position. The air flow is unlikely to turn the switch off but this orientation helps me remember with direction is on. This was the same convention used back in my RC airplane days. We always mounted the electronics switch so the wind was pushed the switch on.
I have replace the antena with a smaller linear dipole antena. removed the sbus wire from dji unit. and wrapped the gps wires with copper tape to shield noise. Not sure if it helps. Got 7 satellites today. I think with my 31/2 inch quad all crammed together may be there is too much interference. I am using 2 18650 batteries. For good position hold and GPS acurracy I need 10 satellites at least. Not sure AIO FC is a good choice may be mini stack is better. Need lots of testing.