I've studied Socionics in depth in the last 10 years to clarify the confusion in typology which is specially visible in the forums where no one knows other people's types neither their own. Even prominent socionists mistype famous people. There is no solid reliable method whatsoever. Socionics is a great theory but lacks scientifical/empirical/material confirmation. I dare to overcome it. People tend to type solely on behavior and stereotypes, which naturally leads to mistypings, cause behavior is vastly influenced by social causes and social personas. The most reliable way to figure out someone's type is by their energy and physical patterns which are genetically connected to the sociotype. Many tried and created VI patterns but 90% of it is either weak or incorrect. I developed a solid VI typing system, and an update to Model A's functional working. I based my model on the studies of multiple eastern socionists.
I don't even know if Socionics is still alive here. The forum is quite abandoned. Just hoping there are still people interested in sharing ideas about the theory.