> Flow state relies on a constant information inflow

Does that mean when I'm in deep thinking without any external "information inflow" I'm not "in flow state"?

I'd agree that waiting for replies kind of pulls you out of flow if you just sit and wait, but I'm not sure why you'd do that. You can continue working along-side, validate, or continue iterating on the design while the agent does other things.

When you're deep thinking you have a constant information inflow that's coming from your own thoughts. This is different from relying on an exterior tool because in that scenario your brain is blocked from thinking by relying on that tool giving it a breather to wander off a garden path. That isn't necessarily a bad thing (it's nice to give your brain a stare off into the distance break every once in a while) but if you've adapted your thinking and working style to the constant inflow and outflow of information it can be highly disruptive.