If you find you are having to let go of one finger at a time then you probably need to shut down parked apps and reboot your iPad. The zoom reset only happens if you initiate a two finger tap event. If you hold two fingers on the device and zoom, then lift only one finger and place it back down the zoom level will not reset. It's likely that either your iPad is bogged down and slow to process taps, or that you are tapping with both fingers when lifting your fingers off.
We won't be removing the feature, but we may consider requiring slightly longer before processing the two finger tap.