TL;DR
Add a way to automatically update existing structures.What ?
Imagine a 5000 tile long stone wall which was built with the help of bots and blueprints.The blueprint which was used to build the wall consists of a 100 tile long stone wall.
Imagine all the infrastructre to build the 5k wall was already in place (robo ports, radars,...) so the player only had to
click 50x to place the 5k tiles long wall. Think about the process of adding laser towers,rails and mines to the now existing 5k long wall.
You have to create a new blueprint with all the new entities and upgrade the wall. Imagine the game had remembered that you placed
the first(100 wall) blueprint 50 times and you only have to upate your first blueprint after that the game would automatically update the already
existing 5k long wall.
This was a simple example but imagine a similar situation where you had to upgrade every single roboport in your megabase with a passive provider chest
Why ?
There are often repetitive tasks in factorio especially later in the game when the player has to upgrade/update already existing structures.I know my suggestions is more of a QoL improvement but it might add a neat little feature which will help a lot of people later in the game.