That is the first time I have heard the AX1200 NOT recommended. Congrats!
I mean, it is a fine PSU, but if you are running it at high load a single rail can be dangerous, as OCP and OVP and all the other protections take much longer to respond if something were to go wrong.
Don't get me wrong, the AX1200 is a great PSU, but the single rail design, is kinda dangerous