So doing some searching on the forums, I have found that for one button building similar to PC requires a device called the Titan One or Titan Two. Before I am willing to drop $100 on the device, I was just wondering if this is correct. I am also curious to know the other functionalities of the Titan Two if someone is knowledgeable enough to share the information. Thanks.
If your mouse has on-board memory and support macros you don't need titan 1 or two. Im using Tt Ventus Z, mouse that supports 12 FULLY programable buttons, even macros that activates if you let a button press down (logitech does not support)
I started to play Fortnite days ago, I noticed the importance of building and I just finish 3 macros for one click build.

IMPORTANT,
First change the ingame setting: reset build = ON.
On my Button layout (PS4)
R2 = LMB (Left Mouse Button)
L1 = Left Arrow˛
R1 = Right Arrow
O (build) = E
˛ I use the Razer Orbweaver, Left and Right Arrow are in my thumb so is very easy for me to switch between items.
Fast Building:
Build Wall: press E, then I press LMB, let it down to keep building (ingame setting
Turbo Build = ON)
no macro needed.BuildFloor Macro:
Press E(↓30ms / ↑0ms), Right Arrow(↓30ms / ↑0ms), then I press LMB.
BuildStairs Macro:
Press E(↓30ms / ↑0ms), Right Arrow(↓30ms / ↑0ms), Right Arrow(↓30ms / ↑0ms) then I press LMB and keep it down if I need more.
BuildPyramid Macro:
Press E(↓30ms / ↑0ms), Right Arrow(↓30ms / ↑0ms), Right Arrow(↓30ms / ↑0ms), Right Arrow(↓30ms / ↑0ms), then I press LMB.
Now I can build a box with stairs in seconds, like a veteran fortnite player and I have only 12 minutes of play LOL.
These macros are as simple/minimalistic as possible, they need that you manually press R2 to build the first piece and /or press build to exit from build mode if needed... there is a reason.
I did create a Onebutton->BuildOnePiece macro and exit build mode directly, and with the
Repeat Macro While Button Press option of my mouse to have instant piece building...
...BUT server lag comes to play and messed up the macro. Longer timings fix it; but is no as efficient o reliable or faster as if you place the first piece manually and exit from build mode when needed.
OK hope it helps.