Earlier Dan Larimer have suggested the gradual forced redemption of SBD for Steem Power, which, if implemented, should make SBD more stable.
https://steemit.com/steem/@dantheman/steem-dollar-stability-enhancements
While the forced redemption hardly would be accepted, the voluntery might work as intended as well.
I mean, when being in the haircut area, by doing convertion we might get a check box to choose whether we want to get 90/80/70/60 cents for 1 SBD liquid, or to get 1$ for 1 SBD, but locked in Steem Power.