My confusion is in the NFT area.
I know NFT is still a buzzword but since the bonds are supposed to be tradeable, you want to have a reasonable amount of fungible token classes.
In plain English: let's have a SEP28 token that represents a bond that pays out 1 HBD on 01/Sep/2028. Speaking of reasonable amount of classes, you do not want a 28AUG28 token (at least until the thing really grows). If you buy SEP28 on 28/Aug/2023, the blockchain will gladly compute the correct price for you off the (witness-signalled) 5-year APR.
NFT can be thought of denoting contract.
It is going to become more commonplace as tokenization of financial assets occurs.