Sorry to reply so late to this thread, but my understanding of the zwave network heal is that it is unnecessary unless your network topology changes significantly.
I was having issues with sluggish behavior and turning off the heal resolved it. Here is a link to a discussion about it:
If my understanding is correct, and please speak up if I get anything wrong. Battery powered devices do not participate in the heal, as they cannot be “told” to wake up and participate. To conserve battery power, they only wake to send reports. The heal rebuilds routes between the mains powered devices. So, if you have three zwave bulbs (mains) in your living room, for example, your network heal runs nightly and rebuilds the routes between these devices. But think about that. If you have not moved these bulbs, what’s the point of trying to rebuild the routes again? If you move any of those bulbs to another room, then it makes sense to run the network heal. But if you add a battery powered device, I don’t think a network heal would be meaningful. But I could be wrong. My network heal has been disabled for quite some time.