I agree with Ian about how the arranger gives us choices.
In fact, imo the difference between a cheesy arranger performance and a pro sounding one has a lot to do with how we utilize the auto-accomp parts and integrate them with our live playing.

In general, for live arranger kb performance, I too prefer the scaled down approach so initially strip down the style to bass & drums only, and then selectively & sparingly add additional auto accomp parts as desired. I also make certain to MUTE all the auto accomp instrument voices that I play entirely live, typically the keyboard and/or guitar parts. Another important element to deliver a truly pro arranger performance is to 'never' allow the auto accompaniment to supply the lead melody by itself, especially in the intros and endings. After figuring what to play or improvise live during the intro & endings, I then delete or mute any lead lines included in the auto accomp. Another option is to retain the auto accomp's intro/ending lead melody line and simply play something live, like perhaps harmonizing over it.