Make the Form designer to work on a specific area of a form and not on all the form

BIZ BIZ Feature Requests
1

Hi,
Today a form Design is linked to a whole form.
I could be interested to make it active not on a whole wform but only in a TWinControl or specify its rectangular area of Action.
The main advantage is to be able to separate easily the area where you want to design from for instance a toolbar that shouldn't be touched
Best regards

Armindo