Yes to both. I also wear an Apple Watch with the main display being a heart rate graph to monitor my stress levels over the day. I tend to average a resting rate of 100 bpm during periods of higher stress, and between 60-70 in periods of lower stress. Longer periods of high BPM indicates that I need to take a break.
The PTSD presents mostly in incredibly severe trust issues, periodic nightmares related to events, depersonalization, sleep problems, and paranoia. I also have an absurdly overblown startle response that looks more like a panic attack than someone being jump-startled. If I'm startled "badly enough", it triggers a panic attack. "Badly enough" can simply be someone tapping me on the shoulder when I didn't notice them coming up behind me.