Hi there 
i built two quads, both INAV powered:

one is a 4" Omnibus Nano v1, deadcat style frame, 1406-2600kv motors and 4032/4045 propellers. ESC Hakrc 25A, Eachine TCX23 switchable VTX, Runcam Hybrid.
Bn-180 GPS and an unknown, cheapQMC5883 compass, Oversky sbus rx for Flysky. A long multi antenna 3,3 Dbi.
This quad can fly well with LiPo 3s 850mah and with 4S LiOn pack 3500 Mah as well.
Weight 212 grams without battery.

   

The other one is a whoop, after some testing i definitively remove the ducts: too much noise and loss of performance due their 60 grs of weight to add to the total of 265 grams without battery.
Tha FC is a cheap but fully functional NOXE V1 + its matching 25A ESC, four 1507 3750 Kv motors, Eachine TXC 23 vtx, 3 DBi stubby antenna, Foxeer 1200tvl cam, FLI14 Flysky receiver. This one has a sporty attitude with LiPo 3s 850mah, but with the 4S LiOn pack 3500 Mah is a flying brick.
   

Now i'm ready for the first flights.
I have the same controls configuration for both Uavs: 

sw1: ARM-DISARM 
sw2: ANGLE/ANGLE+AIRMODE/ANGLE+ALTHOLD 
SW3: ALTHOLD/POSHOLD
SW4: failsafe (landing)
sw5: BEEPER 
sw6: RTH

I know, a weird setup but will help me to test the POSHOLD and RTH features without problems. (i hope)


so i need some tips:

- CONCERNING RTH LANDING SPEED(S) , In which scale are expressed? Cm/sec?. The default settings, works fine for a quad? If not, someone knows some good values for quads?  Once landed, can i disarm the motors to stop them , they will stop by byself, or they will continue working like in "FAILSAFE LANDING" where i can set the stop delay?

- ALTHOLD AND POSOHLD PIDS AND TUNING.  I read this:

PIDs affecting altitude hold: ALT & VEL PID meaning:

• ALT - translates altitude error to desired climb rate and acceleration. Tune P for altitude-to-velocity regulator and I for velocity-to-acceleration regulator
  
  
• VEL - translated Z-acceleration error to throttle adjustment
  

 
PIDs affecting position hold: POS, POSR PID meaning:

• POS - translated position error to desired velocity, uses P term only
  
  
• POSR - translates velocity error to desired acceleration
  

There's the need to change or tune this parameters? When?  They affect the sensitivity of the automatic corrections? 
Really i don't understand.


-MC-BRAKING MODE! What is this stuff? Is a FLIGHT MODE or a feature? How it works? Needs a potentiometer or a switch?

-And the last question: how TURN ASSIST works? is something like the DRIFT in arducopter?

Thanks in advance for your interest.

Well, if you want something done, do it yourself: and the best way to have answers is testing.
i set all the stuff and made changes in my radio switches:

SW1: ARM-DISARM
SW2: ANGLE/ANGLE+AIRMODE+TURNASSIST/ANGLE+AIRMODE+TURNASSIST+ALTHOLD
SW3: POSHOLD/MC-BRAKING
SW4: FAILSAFE (land)
SW5: BEEPER
SW6: RTH

Turn Assist is a COOL feature that make the quad movements very smooth and fluid, expecially in ANGLE mode.
I tested it indoor with and without ALTHOLD and the quad flies really well, is a bit stolid due the ANGLE limitations i set (45° roll 42° pitch) but i want to increase these values gradually, once i got used to the behaviour of this small UAV.

MC BRAKE is a brake: set together POSHOLD is a true panic-button, stops and locks the quad quickly keeping position and the altitude. Cool as well.

Need to test RTH and its Landing Speeds...