@PopQuiz, I was able to solve that problem like this.
It looks for known WiFi networks on boot up and if it doesn't find one starts the softap and starts listening for new credentials, after which it performs a system reset. In the meanwhile it continues to run loop code in parallel.
If WiFi info ever changed (router was reconfigured) I guess I'd have to reboot it to give new credentials. Maybe you can improve on that part.