HST ActAsOne?

[DJF3]

Team,

One GroupBox that I have always asks "Select a device to assign to this template" ? I have no clue why.
The other GroupBoxes don't have this. The difference between these GroupBoxes (saved as custom templates) seems to be that "ActAsOne=False"

In HS Touch the group box properties has an option "ActAsOne"

When searching (Google, HS Board, HST Help) there's nothing that explains what this does?

-What does it do?
-(unless I have looked in the wrong place): Why is there no help available for this field?

Thank you