Zero Sideslip Technique?
John, I recall an article in Aviation Safety a decade or two ago advocating this technique in twins, especially light pistons where that extra 50 fpm may be critical.
One point in the article suggested a yaw string would give better information on sideslip with OEI than the ball.
I guess from your post that transport category a/c have fat enough margins that this potential gain is neglegible when there is already quite enough workload.