Another problem with the tags hierarchy. It is actually only a tags hierarchy, it helps organize tags, but it doesn't provide a notes hierarchy. For example, I have a tag Family, then I have sub-tags Family_member_1, Family_member_2, etc. If I filter notes with the tag Family, notes that don't have this tag but only sub-tags (i.e. Family_member_1) don't get into the results. I have to assign the whole thread of tags to a single note every time if I want it to be returned on every level of the hierarchy. I was advised here to use templates with pre-assigned tags. To make it work I would need a template for every single sub-tag of the lowest level (or every level?). Other related features also don't work effectively: notes count (notes of lower levels don't add to higher levels), and sorting by notes count.
P.S. Sometimes EN feels like it is still in the proof-of-concept stage of development.