How do you know if your contacts use Signal and know to use that app instead of SMS/Messages or whatever?

With the SMS integration it was pretty easy because it would just switch over if the other person had Signal or if/when they signed up in the future.

What's the workflow now? Manually ask them on SMS if they use Signal? Just try it and see if it works?

This sounds like one of those "Don't Worry! Rejoice! We're breaking your things!" announcements that hasn't even thought about how people use Signal IRL.

I'm going to stop my monthly subscription to Signal Foundation.