Korg: long press on Songbook, hit Write, then OK. Even when style is running. Pretty tough.
Yes songbook was a big improvement if you use it.... but it's the antiquated rest of the
"folder system" OS which I always disliked and hasn't changed in decades to many pushes Grrrrr
My vote on OS ease of use to
save info on Arranger kb is ..
1- KETRON
2- ROLAND
3- YAMAHA
4- KORG