Interesting approach. I am for a instant power down for a 5-10% burn fee. (Agree with @Jrcornel response- with multi-factor identification and and white listed accounts etc... as protection against hacks) - is a instant power down even possible on Steem, or is 5 days the quickest?
I’ll think of this idea more and give a more detailed response on my thoughts.
Whatever the decision is I highly agree to postpone the change until after the SMT hardfork.
Instant power down is a security risk. If your account gets hacked the attacker can take 90-95% of your SP instantly and you lose everything.
The instant power down + burn fee could be optional. If you opt-in, you are sacrificing increased security for the ability to exit quickly.
Personally, if I had a second account that was whitelisted for me to withdraw to, an alt account (future could be a light account), for example, that would be fine for me. We can set it up so that anytime that whitelisted withdrawal address is changed, it takes a week before you can withdraw again. So even if my account was hacked, they could not instantly power down and send it to an exchange.
I'm not sure if we can have 2FA on withdrawals? If so, that would be another great feature to have, regardless of instant power down or not. Something like what ledger has, where you need to click ok on your physical device before the withdrawal goes through.
To be transparent, I feel these are changes I would like as an investor, and what other investors might like also. But, people do bring up good points to me how new people would want the instant power down, click on a scam link and get their account drained. And that would be terrible PR for Steem.
So I am not sold on the instant power down from an overall perspective. I do like to try and think of ways to get the cake and eat it too.
5 day is to prevent someone from an instant power down -> power up new account and double-triple-etc vote on the same post with the same stake.
That could be sorted. For example nobody can start a powedown procedure unless their VP is sitting at 95%+...
Although now that I think about it someone could technically do this since posts pay out after 7 days, hmm. Don't remember what the exact thought process was behind making undelegations 5 days but it was something about preventing "double votes" AFAIK.
VP regenerates in 5 days, the post payout window doesn't matter.