https://coinmarketcap.com/drk_90.html
Yes I know this is not us and its a different coin, I only bring it up to show what can happen when 10% of rewards where shifted to Masternode payouts. Because its the only other real example around, sometimes it good to look at others who have done it. As well as for us to guess what will happen when we do it and what could happen.
So why are we trying to under-replicate? Do the entire 10% and add it to the coin cap. 220 million. or take 4-5 years off PoS. It still wont affect the price that much if we added 20 million over 46 years to the cap for a feature.