This may be an unpopular opinion, but I consider SAFE to be a complete joke. To me, things like SAFE are a big part of why people have so many negative things to say about "Agile". SAFE is too complicated, too big, too prescriptive, and basically anti-Agile as far as I can tell. If you work for a company that uses SAFE, or is talking about adopting it, I'd suggest running for the door as fast as you can.