Custom Control Class Clarity in IDE

When you create a custom control class based on a canvas, is it possible to see more than just a rectangle in the IDE?
Because when you have lots of custom controls the layout of a window is getting confusing and not very clear

At the moment this is not yet possible, but Xojo plans to support such a function in a future version.

The best solution right now to make the layout easier is to assign a backdrop image to the custom controls.
Then erase the backdrop In the open event of each of these controls with me.backdrop = nil

a preview draw event would be better instead of small and the same icons.

In fact, an Icon with a red Question Mark inside as adviced by Jeremy and liked by Greg is a good idea.

In the IDE, you have this icon, and if you forget to place your own at run time, you will get a reminder.