Since each monster has 4 abilities, but each ability for each monster does not function the same. What I mean is you have some abilities that are click once to execute, others are either click to aim and click again to execute or hold to aim and release to execute.
The issue with this is some key binds cannot be held to aim, such as mouse scroll wheel up or down. So when you have say, ability 4, bound to mouse wheel up. This would be (IIRC) Vortex for the Kraken and Rock Throw for Goliath. Meaning your Kraken ability will work as it should, but the Goliath would not be able to hold the rock for aiming as if he could hold the button.
So from what I have noticed, you have to rebind your keys from monster to monster if you use mouse scroll wheels for bindings. However, if we could bind specific abilities to different keys for each monster, we can set the skills for each monster ability that does not have hold to aim to the mouse wheels.
Thank you for your time,