When SDO price is above the 1$ peg, the token supply will have to expand to push it back down to 1$ and the contract will allow the redemption of the SBO.
When the price of SDO continues trading above the $1 target price after bond redemption, the contract mints an appropriate amount of new SDO. This will be distributed to the Boardroom Stakers.
This three token system creates incentives through seigniorage, always pushing SDO towards its peg. SSO is used to redistribute the seigniorage from inflating the asset, while SBO is used to establish a price floor while SDO is in its deflationary state.