Hey @Leif,
I watched the webinar about Signals for Flow. Very good stuff, and thank you for explaining it so detailed 
As you wrote this in this thread, I really struggled to imagine how Signals could be beneficial for navigation, but the examples you gave in the webinar helped. It is basically the same you already explained in View state parameters, but sometimes it helps to hear a different version of the same example to understand it 
It would be very nice to see the things you mentioned in View state parameters and Asynchronous view state in Hilla in the future.