Placing non-researched blueprint items in dark gray locked mode instead of downgraded or missing

When placing a blueprint in planning mode, large holes in the layout are left where un-researched buildings go.
Sometimes we cannot remember what is supposed to go there or what recipe to use, especially if it was somebody else's blueprint.
It would be nice if there was a checkbox in settings or when placing a blueprint to allow placement of un-researched buildings and transports and their recipes intact but locked until researched.
This could be indicated with a dark gray ghosted building (locked) instead of a light gray ghosted building (paused).
Thanks