Factorio Forums

Couldn't find a built-in way to do it myself, so asking here incase someone has already figured it out.

So to explain what I'm talking about let us say we have 2 types of science packs A and B.
We also have some technologies
Tech1 - requires 1 pack A
Tech2 - requires 1 pack B
Tech3 - requires 1 pack A and 1 pack B
Pack B is set up to also work as pack A but pack A is not set up to work as pack B.
In this situation the options to research the technologies would be
Tech1 - using 1 pack A
Tech1 - using 1 pack B
Tech2 - using 1 pack B
Tech3 - using 1 pack A and 1 pack B
Tech3 - using 2 pack B (1 for pack B and 1 for replacing pack A)

Wondering about the feasibility of making a mod that permanently removes access to a science pack but also introduces a one replacing it and also unlocking new technologies not researchable with the old one.

That's not possible directly, you might do something to replace science packs in labs by script, but it seems complicated and error prone. You might also make duplicate technologies that use different science packs, sync their progress, and switch between them automatically or let the user pick one of them

Presuming using science packs as recipe ingredients is allowed, you could make it possible to assemble Pack A using Pack B as an ingredient. It's more rigid than your idea, but it does allow you to cascade down from more complicated packs into simpler ones for example.