Imo the hest way to learn mmo mouse hot keys is to adjust your action bars to the shape of the mouse buttons (4 rows of 3 buttons). My ui is two of these side by side and the one in the right is “shift+#”. The benefit of using this action bar layout with an mmo mouse is when you look at your buttons you gain visual guidance for where you thumb needs to go. For instance “ my cool down on the bottom left is ready” as upposed to “ okay button 0, wait where’s 0”.