Causes the panel to re-layout in the next frame. During the layout process PANEL:PerformLayout will be called on the target panel.
You should avoid calling this function every frame.
Using this on a panel after clicking on a docked element will cause docked elements to reorient themselves incorrectly. This can be fixed by assigning a unique Panel.SetZPos to each docked element.
Issue Tracker: #2574
If true the panel will re-layout instantly and not wait for the next frame.