You wrote in your five favorites blog post, “I work with another 21 species either prospectively, meaning that I would like to breed them but haven’t managed to get them to reproduce sexually, or on too small a scale to consider the work serious.”
Can you list what those 21 plant species are? And maybe a few sentences as to your current status with them?
As interesting as it is to know which projects have worked well for you, it would be equally as interesting to know which projects have not yet succeeded and why.
This might be helpful to you. Perhaps someone - somewhere - has observed a plant with the traits you need for a project to become successful.
Actually, if you have the time, this might make a better blog post than a forum reply.