I am not knowledgeable about masechtot ketanot. Wikipedia writes they are essays from the Tannaitic period or later dealing with topics about which no formal tractate exists in the Mishnah. I understand from this question they have been translated in English but not in recent times.
I'd like to better understand the centrality and relevance of these masechtot. Does the gemara make reference to them? Do later halachic codes rely on them? Would some of these tractates be considered important required reading for an educated Jew?