From my experience mapping, I think it would be beneficial to have an audible or tactile notification in the app when GPS signal is lost or established. The existing icon / text message is difficult to see in bright day light, and to be honest, I am typically more focused on the rover than my phone’s screen while mapping.
When the signal is lost, I could immediately stop. Then possibly do other things while waiting (after a long time) for it to be reestablished.