Song Master Pro has the option to either do,a four part split (guitar and keyboard as a single stem) or a 6 part split which separates guitar and keyboard. I just did,a,split on a Kristofferson song and it was a perfect split of guitar and keyboard. Most splits I've done have worked very well.

Although they say you get the best quality from the 4 part split. I'm certain it greatly depends on the source file.

A link from google:
https://aurallysound.com/products/song-master-pro?srsltid=AfmBOoqPNdNe8_pblUbS7ipJxPBY2borFnr_EYgTlolvcQ-wNi1P6HEr


Focusrite 2i2 2nd Gen
Windows 10 pro 1709 16299.125
Intel core i7 6700k CPU @ 4.00GHz 4.01 GHz
16 gig memory
BIAB UltraPak version is 2025 (Latest)
Cubase pro 9