Now the Logic Builder viewer has two modes: mouse and trackpad. So if you are using a laptop (basically trackpad), it will be easier for you if you switch to new Trackpad mode.
You can then use two fingers to pan and pinch to zoom in and zoom out.
Feels much natural. 
One more thing...
Now when you click on the "logic" button from the builder the currently selected block's logic editor will auto open. QoL improvements for users with large number of blocks and complex logic forms.