Want to enjoy learning the new mechanics at my own pace so I'm thinking of a peaceful first run before second run having enemies turned back on (I can't just say biters anymore!). Anyone else in a similar mindset?

If you are playing with sound enabled (or are able to hear) then it is easy to tell when turrets have engaged and/or buildings destroyed, as you get an alarm as well as the small warning triangle and arrows. If you do not have sound enabled/are not able to hear, then when focused on the task at hand...