For suggestions, I might suggest moving the { and } keys to the first symbols page, perhaps swapping them with the & and @ keys (both of which are rarely used in QML, and & is rarely used in Python)?
Also, I don't know if this is something you can fix, but I've noticed that often when I hit shift, it shifts and then unshifts immediately causing the next letter to be lowercase - perhaps it needs some sort of debouncing logic?
Would it be possible to add text selection/copy (with shift modifier; maybe even 'jump to word ending' when it's in caps lock mode) to the arrow keys?