Is it possible to split the Piano roll in order to isolate real notes from keyswitches for instrument articulations ?
Why not program and use expression maps instead? Or is it that you have an old midi file with key switches you’d like to edit out?
The main cause is that I own Cubase Artist 
so, I miss the expression maps feature for my EWQL banks…
Well, in this case in order to make lower keyboard more accessible, you could open your midi part in the in-place editor in the arrange view, open the respective key editor and place it underneath the former. Then scroll each editor to focus on the desired keyboard range and check “Link editors” in the program preferences, but frankly, do yourself a favor, upgrade for the full Cubase and start exploring the power and elegance of vst expression.
I had an idea : create a second midi track dedicated to the keyswitches…
I don’t know if I can route it to the same instrument track…
Perhaps I can also edit this track with the drum map editor in order to write articulations names on the left side…
Concerning the full version I’m asking myself if the investment for this single feature is a good financial idea…
In addition, I don’t know if the maps for EastWest exist…
They don’t necessarily have to exist. You can program any expression map for any instrument yourself.
Does it work with keyswitches or with midi channels ?
It works with both. It actually goes much further than that and, depending on how your vst instrument can be set up, it can create complex rules for controlling articulations.
Thanks a lot to you 