Crew skill: Repair and Logistic

Hi, what exactly do the crew skill “Repair and Logistic”?

I have skilled this to max repair rank (level 5) and speed, but i dont get any free repairs.
How much free repairs can i have is there any limitation?
There are missing example descriptions.

How this exacly works, do i need to disable auto-repair but after fight i need to wait about 3 days i can play War Thunder with this vehicle again?

You can disable the auto repair and the time spent “manually” repairing with the crew will lower the SL cost of repairing that vehicle instantly. So if you get destroyed and the repair cost is 2000 SL but you wait for the crew to repair it half way then you can pay 1000SL to repair the rest instantly and play with it.

At least that is how it worked last i checked.

Pretty useless feature to be honest, like keen vision. Perks that waste points and does nothing significant lol