Thanks you Stevethefiddle
After test, all is right.
But just a little remark.
If I select full track (and only full) ; the factor is multiply by the duration track.
Ex : Track 10.0 sec ; factor 2.0
Result, track is multiply by 2.0x10.0 = 20. 0 instead of 2.0
But full track, less “Epsilon” result is right.
So it does. I presume this is one of those behavioural abstraction things that I don’t yet understand.
I’ve not really got my head round using the transformation environment.