TL;DR
Add a research node that is auto unlocked and all red packs "need" it.What ?
This research node would be connected to all the others, causing the red pack research to be all part of one tree, not a bunch of separate trees.This is a rough example of what it would sorta look like.
Why ?
This would be useful for new and returning players. I often have used the tech tree to figure out "what should I do next?" in reference to building a completely new thing on the assembly line, or making sure I had all the stuff that I'd just handcraft in my knowledge and that I had it equipped etc.The tree is useful because it connects and visualizes the connection between all the techs, while them just being smushed together on the left isn't much of a help for visualization. Also, because of the fact this feature would be aimed at newer players, it would go somewhat unused as a mod, seeing as new players are pretty unlikely to be playing modded off the bat, especially if they're generally "casual" gamers.