Ok, please bear with me while I run a couple scenarios by you to try and understand a bit better.

So let's say at the moment Person A had the ability to upvote a post $1 at 100% upvote power. When implementing the 90/10 upvote/downvote ratio, will they maintain that $1 upvote power and have a $0.10 downvote power? Or will they now have a $0.90 upvote power and a $0.10 downvote power?

The other way I could have understood it would be like this:

Person B has the ability to upvote a post $1 at 100% upvote power. After implementing the 90/10 change, they still have the ability to upvote a post $1 at their max voting power, but they will now run out of voting power 5 votes sooner (90% becomes the "new 100%"). Likewise, they can downvote $1 at max downvote power, but this diminishes rapidly as each vote would take away 20% of their flagging power.

If one of these is what you were talking about, please confirm. If I am completely mistaken in my understanding, please let me know that as well.