Hi,
I'm forever trying to work out what backing, works best for a new song, or learning the chords & melody at same can be a bit a bit difficult, so my set up can be handy for practicing melody part.
I basically now have 3 to 4 options, Korg PA3X, my old psr1500,
Band in a Box realtrack & midifile styles. ( To me some of the Band in a Box Country realtrack styles sound better than the keyboard styles.)

Anyway, I've managed to set BIAB up to play the chords on my keyboards ie I type chord progression for song into BIAB,
I choose a style on either one of my keyboards or Band in a Box
press play, automatic backing.
Gives me the option of concentrating on the melody part, I can change the variations to hear what sounds best etc etc.