Hello,
Based on my experience, I suggest asking for the phone number that will be calling you in case you get disconnected during the test.
It is definitely worth asking PearsonVue if they'll use phone/ or chat/ or both and how many times they will try to contact you in a case of a technical glitch before they close the exam window.
In my case, my screen did not have any indications that my proctor no longer was connected to my computer. She was trying to reach me but I did not dare to move out of the camera view little less answer the phone.