yes i know...i never tried to use C-AF+Tracking. Only C-AF...ok...but when i nanage to keep the focus area in the bird..THEN it doesn't matter if i use +2 or -2No, that is not right. If you manage to keep the focus area on the bird all the time it will make no difference, as you say. But if you lose the bird for a moment, then with +2 the focus will quickly decide to start changing, which will mean it takes a long tiime to acquire correct focus again. You will probably be better off setting it to 0 in this case, which is often the best compromise.
The Olympus C-AF setting is not to do with tracking. Perhaps the other cameras have additional settings to do with tracking.
independently of the speed th bird will fly with and of the direction`This is excatly what i do not understand. One setting influences different behaviors...as you ca read here High-speed Performance | OM-D | E-M1 Mark II | Olympus chapter "5-level C-AF tracking sensitivity settings"...there is "Blocked shot AF response" AND "Subject motion" BUT i only have ONE Setting "C-AF Sensitivity" and not two settings one for "AF Response" and on for "Subject motion" THIS is why i m struggeling with this settings....hope you know, what i mean