There are more than a dozen different tech lines associated with missiles and the missile design doesn't necessarily include that information. For example, the missile has warhead strength, but not warhead tech, or endurance but not fuel consumption tech, or active sensor strength, but not sensor tech.
To do this, I would have to maintain a record of every tech that went into designing a missile, not just the missile characteristics, or add considerable code to try to reverse engineer it and work out the tech. Neither is a quick option.