Hi panos and stefanobean.
panos, it is a WRONG explanation of how a fill works on Yamaha!!!!
Any Fill In in Yamaha it's working like that:
If you press the button between first and second time you will hear ALL channels playing.
If you press it After second time ONLY Rhy1 And Rhy2 channels will play, any of other channels will play the Main which was triggered from
This is how a fill in works in Yamaha.
Yes, Korg has 2 options of how a fill triggers, immediately or next measure, but also, if immediately is set for the fill, anytime when you press the fill will play ALL channels, from the bar was triggered, which can be an option in Yamaha, too, if Yamaha engineers listen for ALL users, not only from some countries
Regards,
Vali