I particularly not in favor of using a reward for just holding a stablecoin for 3 days in staking, as it does not create any value for Hive. It should better be used as a bond and money used for development for Hive or generating more fund.
It only create more Hive and more HBD through stabilizer and it has to balance $1 of HBD to Hive tokens all the time which is quite a complex mechanism but generates more and more tokens that goes into market to become liquid.
HBD Stabilizer cannot issue new Hive or HBD. It can convert them (I don't know if it actually does or not, I thought it only trades there and back), but that's something anybody can do.