Adding a custom chain for testing

[SamWilsn]

Hey! First some background: Wallet Test Framework has received a grant to include mobile wallet support in our testing tool, and Unstoppable is the first wallet we've chosen to work with. We've started the process of automating Unstoppable (see here for a video), but we've run into a roadblock: adding a custom chain.

Is there a way to point either the production or locally built app at a custom chain for testing purposes? Note that this would need to work for WalletConnect as well.

Thanks!