I came across the feature while using a beta of iOS 14, so can't speak to whether it's improved since iOS 13. But my use case has involved connecting to a remo

I came across the feature while using a beta of iOS 14, so can't speak to whether it's improved since iOS 13. But my use case has involved connecting to a remote host over a ZeroTier[1] VPN, using an iPhone 6S. I haven't experienced the scenario you mentioned; most problematic issue I've had is sporadic latency spikes during folder navigation. I haven't really done any true stress testing of things, but it's handled transitions between wifi and cellular network without any noticeable issues.