As you said, right now, fasthax only works on 11.2
So you can update and use the zoogie's safehax (it's safehax with fasthax implemented)
or use the version listed on 3ds.guide (that is, running waithax and then the clean safehax)
What to do is up to you though
The problem is that bbcali89 just updated to 11.2 in order to use the fasthax+safehax pack... but still black screen... :|