Why develop 'arranger technique' when one simple footswitch can negate the need to? I still do a fair bit of actual playing in the LH, especially in Pianostyle mode (even when I'm not playing full piano) where you can play a couple of notes without retriggering the chord...

Instead of making the arranger do a 6/9, you can have it do a straight C and ONLY your LH part add the extensions. It's cool and subtle effect. But you can't do it if you are constantly diving off to hit the fills... The way to avoid the arranger's repetitive nature is to play as much as possible, not delegate it ALL save the RH to a machine, IMO...

And you STILL haven't solved the problems with tunes that constantly change chords (as much jazz and standards do). One bar's fill quite often has a different chord for each BEAT When have you got time to hit any buttons?

Sure, simple stuff you can get away with that, but it gets harder and harder the more complex stuff you play...