Regarding my experience with SBRT, it is now three weeks and I have had zero side effects.
I have read that SBRT is typically between 3 to 5 sessions. In my case, they could do in three sessions in three consecutive days, maybe 20 minutes a session. My skin did not burn or even become red. I cannot tell where the radiation went. I did not notice any extra fatigue - I am still recovering from surgery in May so I deal with shortness of breath, nerve numbness.
Doctors did advise me that with radiation there is the risk of bone thinning and potential skin cancers. So, I will just be attentive for that in the future. Especially because I expect to do additional treatments for other nodules.