This allows you to temporarily toggle the visibility of non-visual components on VCL TCustomForm designers. The effect is only temporary until you close the form, but should allow you to visualize the form without any non-visual components present. Note that the non-visual components are not actually removed from the form, so you can still click on and select them, if you know where they are located.
Note: This tool only works for Windows VCL TCustomForm and TFrame designers (not data modules, CLX forms, .NET forms, etc.).