On the iPhone it's easy to see when ML is syncing or communicating and I generally wait until it's finished before trying to change anything. On the iPad with ML HD it uses up the whole screen so there is no indication when it's communicating.
Yesterday I thought the thermostat was failing (known issue) because I couldn't update the setpoints. Turns out it was taking a little longer than usual to sync up with the ISY which I couldn't determine because there's no indicator.
Perhaps you could consider some kind of indicator, it can be small like the iPhone one on the iPad in HD?