I think a good solution good be to ditch SBD but not to solely display the paid out Steem.

Instead display additional information in the form of an constantly updated real dollar price.

Displayed author reward: 100 Steem (currently worth 101 USD) 

By displaying the current value even the articles which were written when Steem was valued 6 cent, would now show high(er) rewards. It would also promote the idea of striving for a higher market cap as it will highlight how user funds are affected by a price increase.