Hi Logain,
I didn't mean to scare you with that quote. It was meant to inspire you
I think those under 30 are considered young in the AA world. The 30's are still young-ish. Whereas those of us over 40 are considered old for AA. So, the likelihood of your wife responding again to hATG or rATG is probably pretty good, which is why the paper recommends it for relapsed young AA patients without a matched sibling donor.
I would strongly encourage you and your wife to watch this video by Dr. R. Tiu, entitled "Aplastic Anemia: Current Thinking on the Disease, Diagnosis, and Non-Transplant Treatment":
https://www.pathlms.com/aamdsif/courses/776
Dr Tiu is an excellent speaker and a very compassionate doctor. The video will touch on many of the issues that you are debating. Be sure to watch the Q&A session at the end. There is an inspiring 25 year hATG survivor who is now approaching 80. There is a woman who speaks of her daughter who survived a BMT and is now at year 15. There also is a person who had rabbit and then hATG. It is just a very relevant video for you.
There is also a very timely live webinar coming up on May 12th that you may consider viewing, depending on your time zone. It is called "Aplastic Anemia: Why Treatments Work and Why They Don't". It will be discussing the tradeoffs between BMT and IST for the treatment of AA. The great things about the live video is that you can ask questions that the speaker will address at the end.
https://www.pathlms.com/aamdsif/webinars/920