In Rhino 7, you can click on any icon, expand its cascading toolbar(s) and activate any tool located there upon releasing of the left mouse button. You can even do that on multiple cascading toolbars, all with a single mouse click!
In Rhino 8, you are forced to click and hold the left mouse button on a main icon, then quickly release it in order to expand its cascading toоllbar. Then, you have to release the mouse button, hover the mouse pointer over the desired icon and them click the mouse button again.
Rhino 8 “punishes you” if you try to hold the left mouse button on a main icon and then drag it over the desired icon located in a cascading toolbar. This is contrary to the perfect way of expanding toolbars in Rhino 7.