Maybe I did not express myself exactly enough:
My projects are approximately 35 to 60 Min. long.
I´m working on sounddesign, Postproduction, Real sounds...... AND
I am Composing the music for those films (TV)
In the end I work with up to 150 Tracks in one Project.
When I have a ready Part on Track 5 with Automation and a few minutes later I do need Track 5 for something else which should be automated too I expect that Latch Mode works as described in the manual (from Logic Pro Help)

Which, by the way worked superb until Logic 9.
It is not helpful at all when that "feature" works only once in a track with no Automation on it....
Because that means all the work previously done on that track has to be deleted to make sure it will work from that point on.
Sorry but that does not make any sense at all and its everything but Logical.
Another Example:
I have a long "Atmo" like a wind through leaves in a forest with birds etc. and I need it for about 4 or 5 Minutes.
The level does not change within that time only at the beginning with a slight fade-in.
In former times I automated that fade until the level was fine which was after 10 seconds (latest) and from there on the level must not change.
I just don´t have the TIME to let logic run for 5 minutes when there is nothing more to do on that track.
When I stop Logic after writing the level in Latch mode now it JUMPS Back to the level from where I started and I have to erase that last Automation point. And this is whats really annoying to me.
but anyway thanks for your tries to help me.