Factorio Forums

If you open or create a blueprint and select the upgrade planner in the top left it will offer several down- and upgrades for belts, but:

• "Downgrade to Blue Belts" is missing completely
• "Upgrade to Green Belts" is also missing
• Downgrading green belts to yellow/red/blue does not work

As a minor feature request: It would also be nice if the upgrade planner offered options to:

• Down- or upgrade between the different inserters.
• Down- or upgrade between different assembly machines.

It's offering you applicable planner from your library.

When holding a (simple?) upgrade planner, after dragging it, don't release the mouse button yet, but first hold Control to turn it into a downgrade planner.
(I can't believe it took me several thousands of hours of Factorio to learn about this, when was this added ?)

Thank you, I didn't remember that I still had those.