boromir said:"naval base trades", "temporary" != permanent province exchanges
And as for the AI you mentioned in another post, based on previous Paradox experiences, how strong do you think it will really be? Not very. So we have a feature, that's fit more for the EU2/Vicky period, being put into a WW2 game, with no basis in actual history, just ripe for abuse.
Then do not abuse it. The "ask military access to attack a third country" is considered abuse in HOI1. That's why I never do that because I consider it a lame tactic.
I can play a game without abusing of every single feature that gives the human player an advantage against the AI and enjoy it the same. And in MP is just easy to have a few house rules that limit this behaviour to what is acceptable by everyone.
OTOH I consider a welcome addition a feature that allows me to partition conquered land between allied nations. If I want to give bessarabia to Romania in exchange of that land in ukraine who is occupied by rumanian forces I should be able to ask ingame instead of having to edit savefiles.
I prefer to have a tool which is sometimes useful and sometimes not rather than having nothing at all.