About the splits: Live does it very well with the instrument rack device (you can choose different ranges in the keyboard for each instrument).

"Instrument Racks Updated for Live 11 Lite Combine multiple instruments and effects into a single device, allowing for split and layered sounds with customized Macro controls"

 

Cantabile is already listed here but their customer support is incredible, I tried their free version and they kept in contact with me for several months with suggestions, followups and offers of help for issues or problems. I've never found any other company that was as helpful for a user of free version and never once trying to convince me to buy their full featured version of their software.