Factorio Forums

Apologies for the horrible subject; the issue is somewhat wordy to explain. The wordy explanation is as follows:

Say I have a blueprint, like this one: Copy blueprint and this blueprint has some inserters in it that have a stack size override set. This blueprint has four inserters that, in order have the following overrides set:

Inserter 0: No override set (this is the group control)
Inserter 1: Stack size 1
Inserter 2: Stack size 2
Inserter 3: Stack size 3

If this blueprint is put down BEFORE inserter capacity bonus 2 is researched, upon completion of that tech, inserters 2 and 3 will each have their stack size override set to 1. Recall that inserter 2's stack size should be set to 2 from the blueprint. Inserter 3 has stack size 3 from the blueprint, so it is fair to say that its behaviour is undefined.

If this blueprint is put down AFTER inserter capacity bonus 2 is researched, then inserter 2 will be correct, and inserter 3 will now remain as the incorrect one.

What I would expect to happen is that if the blueprint is put down before the research is complete that inserter 2's override will be set to 2 once the research completes. As it stands now, the inserters' overrides is only correctly (re)set with a re-paste of the blueprint.

The current behaviour is that inserters' stack size overrides are set to the lower of the values from the blueprint and the current stack size bonus. That only happens when you place the blueprint, so the override doesn't change if the stack size bonus does.

As you note, you can "fix" this by placing the blueprint again, once you have researched greater inserter capacity bonus. This is similar to how a blueprint containing assembling machines (etc) set to recipes you haven't researched must be placed again to set those recipes, once you have researched them.

I interpret your expected behaviour as allowing the stack size override setting to have any positive value (up to the maximum research would allow for that inserter), with the effective value limited according to the current stack size bonus. This seems a feature request rather than a bug; consider the inserter window display and behaviour.

Yeah it's a feature request. It would need to store the "ghost settings" somewhere after the entity is built if they can't be applied correctly, and then check again every time a tech is researched. Would be handy, especially for recipes.
Another, easier solution would be to add the stop sign (that is used to indicate unavailable recipes) to inserters with too high stack size override.