Factorio Forums

Similar to the swapping of chests and smelters, make the player able to swap modules by just clicking on an inserted module with another module (without interrupting extra resource queues by first removing the old module before inserting the new one). This could be made to work outside the building inventory screen as well, just as with the automatic inserting of modules into empty slots: If there are no empty module slots in the building, the module is swapped for another module. It could be the first module, or it could prioritize swapping cards of the same color.

If you have different modules inside (different type, different strength or any combination), which one should be swapped first, second, third...?

ssilk wrote:If you have different modules inside (different type, different strength or any combination), which one should be swapped first, second, third...?

The priority when you swap without having opened the building, I've left upto you. Like I said: You could default to switching only the module in the first slot (provided that all slots are full), or first see if there are any modules of the same color, or maybe even prioritize to swap out lower ranking cards for higher ranking cards of the same color.
The main feature would be being able to swap cards while having opened the building. Anything more is extra.