As a corporate entity, I find it ridiculous that you can make branches in foreign empires, but not in your own subsidiaries. The situation becomes specially ridiculous when you realize that it is possible, if playing with a Criminal Syndicate, to make branches in your vassals, but somehow, it's impossible as a legit Megacorp .We are able to make migration agreements, so we should be able to make commercial agreements too and, if possible, research agreements as well with our vassals. The best option in fact would be to be able to set the autonomy of your vassals through some sort of policy that allows you to allow them to possibly make research and commercial agreements with you, between them and even foreign nations. But for now I will be satisfied by being able to simply make trade agreements with my own vassals.