I'll share this with the team! We were thinking this is the way to do fulfillment since that needs private key access, but it shouldn't be hard to do completely client side. It's been possible for over a year now since we launched magma.
As stated in the announcement, balances aren't required to use hydro. It can work using only public info (capacity).
We'll roll out accounting & audit functions for (primarily) businesses that need third party validations and share balances. Also, pathfinding support for improved payment reliability & insights.