I read in a different thread that the reason the other races would have a delay to speak with the player again was to prevent tech brokering abuse in GC2. How about this solution which would allow the player to trade tech without abuse.
- When a civilization develops a tech, they have the copyright on it. Only the civilization that developed it can offer it in a trade. This way, a player can still trade his tech for alien tech, but the tech he obtained by the alien, cannot be used in a trade with another civilization. Only the tech that he developed.
Unless you can negotiate a treaty with that race which lets you clone each other's tech.