The fee for instant powerdown would discourage exchanges from powering up their customer's funds without their permission.

On the security side, there's been discussion in mattermost for various mitigation techniques. One would be an option to lock one's account against immediate powerdowns. If you then wanted to unlock it and allow instant powerdowns again, there would be a delay before it's allowed. This could be the default for regular users, and speculative traders who want to be able to access their funds quickly via instant powerdown could forego the initial lock against powerdowns.

Any change like this would have to be done in a future hardfork, it's too late to consider including anything like this in HF25, IMO.