...more than $1.00 and there is little the community can do without charging negative interest rates.

It's called inflation. Pump more SBD into the reward pool until the value is $1.00 USD. Maybe $1.05 for an added buffer. JK I'm sure this isn't an option because of the relationship between SBD and Steem. Steem has fixed inflation. I thought that the entire point of having SBD would be variable inflation but I guess not.