Changing Captial

with ES2 direction, it won't be only about changing planets status. Population migration should be affected too, trade routes and stuff. New capital city becomes new most progressive city of a country; same thing should be reflected in the game by both bonuses and penalties (to prevent strategy when user changes capital system few times, one by one bringing prosperity to each part of a galaxy).
Interesting, but how (and for what) you want affect the game in result?

For some playthroughs I find systems that better suit my needs and want other races to migrate to it rather than my unwanted capital planets. For example, I find a system that has 5 desert and infernal planets and very high industry , making it my capital and having other races come there would be more beneficial than having a farm system that is already full from incoming migrants.

Sometimes my capital system is in a very vulnurable location , so I want to change it to protect it as it has the capital system modifiers ( The special buildings).

Among other things.

Even in an immersion point of view it does not make sense why I cannot change my capital...