While this issue is discussing some kind of necessary classification/grouping/hierarchy of the database objects in the database explorer at the left.
Without any comparisons and just by practice of some-kind of a growing objects database HeidiSQL becomes gradually annoying then hard than very hard up to be impossible and unusable at a specific limit. This is not what I imagine, this is what I practiced. Of course it is so sad because HeidiSQL, except this issue, is the best. But it seems that this issue is a killer one. Why? Because it is strictly related to the self-evident truth that growing without classification is a hell.