Sounds like an interesting idea that will shine more light to the DeFi capabilities of Hive. My only concern is, how this would affect HBD supply and debt. If too many users stake HBD, this could become a problem and lead to HBD and subsequently Hive inflation. So a dynamic calculation would be needed to limit the interest rate / inflation rate of HBD savings based on the number of HBD staked overall and the HBD/Hive debt ratio. If debt ratio is exceeded APY should go to zero to limit the inflation.