I'm not sure if it has been suggested before, but I've read the list and didn't find it.

This would be important mostly for leagues.

The team manager should be able to define the pitstop (F12 menu)strategy for their drivers, so the drivers could be focused only on race.

Instead of drivers have to change the F12 values, the manager would have access to this menu, and would change the values himself, forx example when viewing his driver, he could just call the F12 menu and change the values according to the strategy of his choice.

I believe this could be implemented in a way like the actual possibility to change the car driver during endurance races (pairing drivers). Drivers would "pair up" with their team manager.

I like this idea and would expand on asking for team chat. I could choose to block chat in the race, but still see important race information (flags, pit details) and also have chat from those i define on my team.

These are possible with Insim I think, but I don't know who is interested doing this.. I would be IF I knew anything about programming :P
E: and yeah, great idea

Only thing I see usefull is team chat , but tbh I use TeamSpeak3. Team leaders setting strategy would be bad, what if your short on gas or tyres burn up too quickly and you must pit early, then next person will have to short fuel.

Then your team manager adjusts the pit stop settings accordingly, while you concentrate of getting the car back to the pits in one piece.

The problem you just described it more descriptive of removing the f-12 menu and making the players set pit strategy pre-race, not of having another player able to cooperate with you and adjust the strategy while you concentrate on driving.

Quote from Bmxtwins :

Only thing I see usefull is team chat , but tbh I use TeamSpeak3. Team leaders setting strategy would be bad, what if your short on gas or tyres burn up too quickly and you must pit early, then next person will have to short fuel.

The suggestion was not about removing from the driver the option to set pit strategy...

Just take as an example what happens in F1 (or any other racing), strategies are defined by the team leader, but if something happens during the race that needs to change the strategy, will definitly be easier for the manager to make fuel calculations (for example) to determine the additional number of stops and the fuel in each stop.

Making those calculations, and then adjusting it in the F12 menu is not somethig you want to do when having a close race or a dispute for a position (even less in the BF1).