I would actually like to something to help deal with puppets and subject nations to allow me to tard-wrangle the AI better. Something like the EU4 client state system where I can choose how I want to release a nation, what to have it do and more. Maybe I am playing as Germany and want to establish a client state Poland after I take out all the eastern theater but I only want it to look like it did in the Brest-Livotsk treaty and not release everything it has cores on. Or I want to release Belgium as my commie puppet of the USSR but don't feel like also releasing Luxembourg as a single comune and want the Belgium puppet to have it. Tell my subjects to focus on building only infantry equipment and sending it to me, keeping only a self defense army. Or tell them to produce armoured divisions and I will be giving the tanks and they provide the rest. Or telling my Dutch East Indies to focus only on infrastructure and convoy building.
Stuff like that. I am tired of having to paint the entire map with my own nation and forcing a world spanning empire that HAS to be hell to administrate.