Here is how I deal with this problem...
I have problem with my vaults as well. The top part of my vault has a Mr Handy on every floor and a bunch of resources to harvest. I found that if I scroll down to the "dead" part of my vault when is first starts, I avoid the game reseting. The lower parts of my vault just have a bunch of empty medbays, storage spaces and the quarters for the dwellers. I stay there for a minute or so after loading to free up the load on the iPad.
Its not a great solution but its worked for me.
As a possible solution for Bethesda, maybe they can have an option so that there are no graphic animations for caps and resources as a switch in settings. This would probably increase stability.
Definitely this! I'm so tired of opening my vault and having to wait through all the bling animations when I catch up on resources, training, and leveled-up dwellers. And the noise...!