What i really want is 2+ players in the same Agency.
Sometimes i play with a friend of mine, he likes to build different types of rockets, and i like to operate. I often asked him to build the rockets, giving him all the specs i need, then he built it, sent the file to me and watched me doing the tests and doing my missions using it. It was very fun.
We wondered if in KSP2 we could have the same agency, and while i operate in missions, he builds new rockets for new missions. Also we have another friend who will enjoy very much to farm science and controll kerbals on land missions. It would be amazing doing it all together in the same agency, and eventually at the same time.
We also thought about being on different agencies but we could trade rocket projects, science, techs, etc... using money or reputation as currency.