I just received my APEX in the mail a couple days ago, and before that I was using the Titan Two exclusively to play Fortnite BR on PS4 for about a week since my transition from PC. The script I'm using allows me to map one-button building to my G502 perfectly the way I do on PC. I've just set up my APEX and T2 to work together tonight and I must say, it's a game changer. The Titan Two works perfectly well stand-alone for Fortnite, however the mouse input translator is FAR inferior to the APEX.
If you're looking to get a Titan Two for one-button building, definitely give it a shot. I can give you the script that I'm currently using as well. I hope this helps answer your question. Best of luck!