Isn't 6NF essentially a flavor of EAV? I think essentially it is.
6NF means having one non-PK column, so that if the value would be NULL then the row need not exist, and so the value column can be NOT NULL.
But when you need all the columns of what you'd think of as the <thing> then you need to go gather them from all those rows in all those tables. It's a bit annoying. On the other hand a proper EAV schema has its positives (though also its negatives).
It's similar, but instead of one table holding lots of attributes, there are separate tables that hold optional fields that might otherwise be null if they were in the main table.
6NF means having one non-PK column, so that if the value would be NULL then the row need not exist, and so the value column can be NOT NULL.
But when you need all the columns of what you'd think of as the <thing> then you need to go gather them from all those rows in all those tables. It's a bit annoying. On the other hand a proper EAV schema has its positives (though also its negatives).