I find myself spending a lot of time trying to get around usability issues in Blocs. For example: the classes section in the blocs settings panel at the right. If you make custom classes with long names (my-custom-button-blue—etc), it is hard to delete the class, because in most cases the (X) to the right is not visible. So I have to use the backspace key. Add to this the fact that some items have 3 or 4 custom classes, editing and deleting things starts to get pretty cumbersome.
My wish: make BOTH the layer tree and the properties panel adjustable - like Photoshop does. Give the user the choice if he wants a properties panel that’s really wide, or a layer tree that’s really narrow, etc.
In general, I would like to see future updates of Blocs concentrate on interface improvements instead of adding more new features.