I always struggled in doing decent solos with my plugins
Scaler’s Keys-Lock option rarely helps, and Ableton Live Scale feature is good, but solos were always dull
I am not good at keyboards, so unable to add articulations, licks, etc. nevertheless I found a simple way to build decent solos using Scaler, but after in the workflow
Here is the simple trick
You have put together a cool base with drums, bass, and an accompaniment guitar
Set Scaler 2 to receive the accompaniment guitar’s MIDI
and now click on Detect > Midi > Record and look at the matched scales offered
I selected the first 3, dropped them before the solo guitar, then I mapped 3 black keys on the right of my keyboard
Now hit Play and activate those 3 scales at taste with one hand while playing notes with the other hand
This way, your solos will shine 
Well, not certainly like the best axe players around, but funny enough for me