I don't use the ALL function at all. If you are finding something unacceptable, then don't use it would be my advice. The only time I would use ALL is if I wanted to control all engines at the same speed, which I would never want, and never have.
I love the Wi-Fi app. It allowed me to stop using the handheld and never see "engine not on track" again. It also allows me to run all my engines on one app, pretty seamlessly.