All the power to you, and I hope Pi will be able to continue its unified layer.

However, there is an alternative: model the session fully in the provider native structures, extract only what is needed for harness specific branching, and treat a provider switch as a _migration_ that you apply at the time of the switch. So treat a provider switch as a migration from provider A to B, with custom logic, etc. This is IMO a more sustainable model. But I'm aware that Pi, OpenClaw, et al have their commitments here.