Tell me: in your sincere estimation am I likely to regret it if I let you act freely?
I dislike fairy orders and will probably revise the world so they don't work here, or on my children should they visit other worlds. You might desire some of the dead returned to life who would not otherwise have been, or returned to life sooner. You might desire to change the fates of some people. If it is Maedhros's sincere desire to stop existing no one short of me can do that.
Don't attempt to get out from under my orders delivered of my own uncommanded will, nor to prevent me from delivering them. "Oh - you may act freely," she adds to Maedhros. "But please don't kill Sauron, I might need him for something. Eru says if you really want to stop existing you'll need him for that specifically."
"...Yes. What did you think I did?" she asks. "Can I have you around for general advice and consultation while I try not to make any stupid mistakes wielding this deity or should I ask Maglor?"
"Don't anticipate having to with your oath gone," she says. "Eru thinks I might want some people alive earlier than planned or some fates changed."
"He didn't specify. I'm unclear on how fate is supposed to work."
"What do you suppose would happen if I just told him that everyone in Mandos who wants to be alive should be alive?"
"Then a lot of orcs would be alive, and they're not sworn to hate us any more but they have other reasons to, in many cases, and they'd all be in Valinor, and the Valar might just kill them again. 'Alive and somewhere where they have the resources they need to stay that way and no one they have a serious grievance with' would be better but correspondingly less airtight. You could just go with 'alive, and in a way I won't regret.'?"
"Leaves him lots of leeway and it turns out he's not a fan of fairy orders... might have to work more piecemeal. Do you need several decades to say goodbye to your boyfriend before you stop existing, I could start there."
"I can let Eru make them stop working on you, he kind of wants to do that anyway."