Just a thought as I am reading this: Would it be possible to extend the lifetime of construction lines?

Sometimes I use the same construction lines a couple of times, in which case I draw regular lines that are deleted later. But maybe this concept of construction lines could be extended: They are a new Type 'construction' of straight lines and remain on the screen until thrown away. The ephemeral character is what makes them useful: They could be discarded without trimming and deleting.