Increase Exposer behaves differently for collapsed and uncollapsed Peg or Group

Harmony Harmony Support and Troubleshooting
1

I made a screen recording showing behavior of the Increase Exposure which seem subtle and a little non-intuitive.
I observe:

  1. When an uncollapsed Peg layer is selected, Increase exposure only increases the key-to-key durations
  2. When a collapsed Peg layer is selected, Increase exposure increases key-to-key duration and drawing-exposer
  3. When an uncollapsed Group layer is selected, Increase exposure is not available
  4. When a collapsed Group layer is selected, Increase exposure will affect all the layers in the group

I am wondering if this behavior is documented. As you can see by this posting and another of my postings (link below), that I
am trying to get my head around all these complex behaviors, and to grasp how to work timing in Harmony.

4min screen recording of issue.
http://www.the-maze.com/ToonBoom/Harmony-Increase-Decrease.mp4

In a related post:
http://forums.toonboom.com/harmony/support-and-troubleshooting/extend-layers-timing-timeline-vs-xsheet

2

I see some logic to this behavior and the benefit of it acting like this under each circumstance can be derived. I do not know but would not be surprised if this was not explained anywhere in the user guide. The documentation tends to describe what something does without describing why it was designed a particular way. In the past, Lili Vogelsang frequently provided the backstory to many design decisions. It was invaluable.