I must admit I am commenting more because of the Sbd run. However I think a happy medium could work. If we allowed 100 pct Sbd post it would double the supply and should slow (if not reverse the growth in Sbd. I think this would make us more stable but still have a premium valuation. As Sbd becomes more stable it can be used for more things. Another move to make it stable would be to pay interest in Sbd. This would also increase the supply by a small amount. We can likely find lots of small supply increases.
Lastly a variation in your proposal is to allow conversions at market prices . So $7 of steem would get 1 Sbd (if that the price) this would increase steem supply but would increase much slower than a $1 steem = $1 Sbd rules