Hi all,
Sorry you're having some troubles. We do know that this is early days for the workflow, and it didn't really get any chance to be used during public beta, so there are some rough points we'll address for FME 2018.1
In the meantime, one thing I found was that whatever 3D object you put out there has to be centered around 0,0 in X, and the units for X, Y, and Z need to be the same.
I've had pretty good luck taking Sketchup objects from their 3D warehouse and converting them using this workspace:
skp2fme-ar.fmw
Note that it shifts the origin of the model to be centered around 0,0 in X and Y.
I'd suggest finding a simple sketchup model, downloading it, and then adding it into my workspace, deleting my sketchup model and replacing it with yours.
Good luck and let us know how it goes.
Oh, I'll also include the .fmear file I was using just so you can be sure you've got the app side of things working well: https://www.dropbox.com/s/jlu4zare229cgse/Deep%20Dive%202018.fmear?dl=0 -- try downloading that into a file system that the FME AR app on iOS can read and see if you can get that to work.
PS: I do not think you can put just lines or points or even flat 2D areas out to FME AR files. They all need to be converted into 3D somehow. The new Bufferer has the ability to do that if you turn on 3D mode, or use the Extruder.