Definitely much easier and faster to just walk land side from TBIT to T7 then try to do the air side shuttle from T4 to T6. You can also try catching the land side terminal bus A.

Bookmark this site to check where the shuttle is when you exit TBIT. If it is 1 terminal away, you can wait. If the bus is more than 2 terminals away, it will be faster to walk.

https://laxtransportation.ridesystem...outes//7/stops