There could be an advantage for some long time bitcoin holders who wish to hold profit at the current fiat price.  If people did this 3 months ago, the could now sell and double their bitcoin.  If people did this themselves, there would be tax implications that would be hard to hide.  Using a service like this could be quicker and hide profits for a time, but you're also paying for the service.

One suggestion, instead of just fiat bonds, why not the option of gold and silver?  Bonds give a set return, however most bitcoin users believe it's not worth the paper it's printed on.  You could offer both and let them decide.  I've actually converted some profit to gold and silver recently.  There are several places that accept bitcoin.

There could be a small niche here for you, but it's not something I'm interested in at the moment.  Best of luck.