It's not possible at the moment. As the system is currently designed, powering down removes a constant amount of vests from an account, determined by the vest balance at the time of power down. There is **one** conversion rate for Steem and VESTs.... it is used when you power up and when you power down. Inflation of SP balances is really just due to the change in the conversion rate over time... It would require a complete overhaul to basically tax people for powering down.

And honestly, that's not what we need to be doing... If people want to power down, that's great. SP balances get the highest interest. The more Steem held in SP balances, the faster the money supply grows. That's dilution... even for SP. For SP to hold its ground against dilution, the vested level needs to reach 90%

This wouldn't solve the problems created by the hyper inflation because it will still be there. It will probably mitigate the price drop temporarily but it's not a sustainable model. Also what this will do is that it will disincentivize people to power up in the first place. It would also create an environement where people are not equally treated which to me sets a pretty bad precedent.

I understand your mind set craig, you really like your steem power number increasing. And you are not the only one. But you need to understand that the inflation created to give people this fake illusionary feeling of having growing power/share is undermining the system as a whole, as it creates exponential downward pressure on the price of steem.

Actually if I remember correctly you very much understand the importance of VESTS. 
So Im going to try to explain to you how the numbers growing in your account is just an illusion. When your steem power numbers grows your VESTS don't grow, because this steem power is distributed equally to everyone so you are not gaining VESTS when you see those numbers grows. The only way to make more VESTS is to curate or posts content or buy more steem on the market.
When people power down and you stay powered up it doesn't give you more VESTS unless you buy it on the market, all it does is that it reduces the VESTS of people selling their steem power. In other words, powering up doesn't give you any financial benefit other than being able to vote and earn curation rewards.
So if you remove the unnecessary inflation completely, your steem power balance would only grow if you curate or post content or buy more steem. You would be given a much more honest interpretation of the growth of  your shares in the platform ( when your steem power grows your VESTS /share grows) and most importantly your account value is much more likely to grow in value because we wouldn't have this crazy useless printing going which scares away pretty much every investors/traders and kills the price of steem.

Many people think that if users's steem power wouldn't grow there would be no incentives to power up. This is a false misconception as already today the only real financial benefit from powering up is the curation rewards, a growing number of steem power gives you zero benefits. The only people buying steem power for this reason don't understand how the system works and you can be sure that  investors won't invest on steem based on this illusion. 
As I have said in one of my previous post, the 2 years vesting withdraw period's only purpose is to prevent people from selling the highly inflated steem but it's not even clear why steem is inflated in the first place. Here we have a complexe system trying to fix problems that don't exist. Btw I'm not criticizing only I also offered solutions.

Bam! To be or not to be~