There may be a clearer way to express this idea. If you slightly extend a clip in the arrangement beyond its loopable length, for instance, to include the first drum hit of a bar to emphasize the start of the beginning of the next part of the song, the appended section persists when you adjust the clip's end in whole-bar increments. This proves very useful when refining the arrangement.
Without this functionality, you would need to either paste that extra section at the clip's end or manually zoom in and add it each time you make a whole-bar adjustment to the clip length.
Now, ableton remembers your choice and takes care of that when you handle the bigger picture.
Great thinking
![Smile :)](./images/smilies/icon_smile.gif)