More of a change request and I haven’t real tested it, but:
I have a feeling that AIs directly trade after one of them has researched something. Human players also take some time to react/negociate the trade before they actually send someone a technology. So I think there should be a slight delay for those trades.
By the way, when/how does the AI spend its money? And does it pay the exact amount of transfer cost to its AI traders? I’d like to understand how the AI thinks in this respect.