my answers are about the current version.
we have demonstrated the main features in public demos, in order to do it for all features we would need many more demos and I don’t think people would test all of those and also it would be difficult to maintain all those demos.
about documentation we once had a c++ api document but I realized noone ever used it so we don’t release it anymore and we expose all getters & setters to BP so almost all features are exposed to BPs. in any case if someone is not willing to buy due to lack of documentation I respect that but our resources are limited, we prefer to use our time for maintaining the project.