I have witnessed Grim Dawn be criticized about the keybinding “piano” elements. After my G600 broke and I have had to resort to the keyboard to use skills (horrifying, I know) I now believe these criticisms are well-founded.
To avoid having to become a graded pianist, implement keybind modifiers (i.e. holding down alt/ctrl/shift and changing the bindings of other buttons such as 1/2/3/4) and stave off RSI for a while longer.
I apologize if this is already a thing or there has already been an intravenous suggestion, but I couldn’t find anything after my trawl - it seems kind of absurd that this hasn’t been implemented, and is a common alleviation for this issue in other games.