100% of the complexity would be back-end only.
A simple UI would allow anyone with $HBD in their wallet to bid on and/or purchase $HBD Bonds. Similarly, a secondary market for trading those bonds would not require any expertise beyond a general understanding of bond markets.
Investors familiar with bond markets would have no issues, with the primary or secondary markets.
The purpose here is not to get existing Hivers to invest in $HBD. The intention is to add an investment use case that is very familiar to a wide range of investors, and to do it in a way that allows the witnesses to focus on managing a metric (TVL) that is more straight forward and much more likely to ensure long-term stability, compared to managing APY.