Why not copy RPG talent tree system for industry?
Make most things tiered 0-5. You get X amount of points to spend on industry.
Tier 0 is no points, just cost of schematics. Tier 1-5 you need to spend point. Specialization starts at Tier 3.
You can use all your points and be a jack of all trades and take Tier 1 and Tier 2. As soon as you spend Y amount of points in Tier 1 or 2 all other tiers are greyed out and all further points can only be spent in Tier 1 and 2 with enough points to get everything, you are now a jack of all trades up to Tier 2. Leave some item in Tier 0-2 that only jacks of all trades can get.
Plan your specialization and be, for example, an engine specialist. You have to put your points into Tier 1 and 2 engines to unlock Tier 3 engines and as soon as you pick Tier 3 engines all other parts of the tree are greyed out. You can only move up the engine talent tree to Tier 4 and Tier 5 with enough points for everything.
You equalize the points so that all the points needed to fill Tier 1 and 2 is the same as specializing to Tier 5 of one branch of the tree.
You still have to buy schematics, just not so expensive for Tier 0 - 1. Tier 2 is where it where the cost becomes impactful, time consuming, and require travel. The cost of a solo player to specialize up to Tier 5 should be a grueling, mind numbing, dangerous experience.
The cost of materials for Tier 3-5 should be outrageous so new players wont just skip over Tier 1 and 2.
Corporations will need several people to make higher Tier items, and solo players can play without corporations. But they would need each other.
I would go even further, and not allowing jack of all trades to be part of corporations. Any cooperation would be just that, cooperation.