Some of the later assembler tasks require a number of complex inputs and it's difficult to track which aren't working at full production, or to know which item is missing without individually opening each assembler and seeing which items are low. By using an overlay it will allow you to take in the quality of your factory complexes at a glance and help focusing on any bits that need tweaking.
It will also help the use of upgrade modules since you'll have a better idea of which factories are lagging behind, which have enough resources, etc.
The game currently has efficiency on steam engines but it would be nice to see that on assemblers as well. Preferably in a percentage format rather than that green bar
Apologies if there is already a way to do this, I only recently got the game.
