Relates to: #3104

Having the examples on Devnet is best for now—since MPTs are not even enabled on Mainnet yet—but eventually it would be preferable to switch the examples to use Mainnet so that we don't have to re-create the same data every time there's a Devnet reset. Devnet resets are somewhat irregular but can be as often as multiple times per year, whereas on Mainnet we can generally create sample data once and leave it there forever. So that's a task to note for later, but it can't be done until MPT is enabled and there's no need to do anything until the next Devnet reset.