One thing that our model does not reflect is the notion of a self-sovereign identity. We should add this concept and self-sovereign identifier to our model - see https://trustoverip.org/toip-model/ for more details.
Also related to this, we are missing the concept of digital identity - see https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-63-3.pdf for a relatively complete definition and discussion of the topic.
Also, in our bonds ontology, we are missing the concept of Treasury Inflation-Protected Securities (TIPS). We have inflation bond and government issued security, but we have not tied them together to represent this specific kind of offering, which is quite common and was mentioned in business news today as increasing in popularity due to investor expectations that inflation will go up in the near term. See https://www.investopedia.com/terms/t/tips.asp for example for additional discussion.