Sounds difficult, but once you have done it 1-2 times, strictly following the tutorials, it is somewhat easy. You set up an empty scene one time and can use it for all following projects.
Just draw the .fbx to Unity, extract the materials/textures, put the object at coordinates 0/0/0 of your scene, look through the materials, add mesh collision optionally, save, export, copy and rename it to VaM, and it will appear at the spot of your VaM Custom Unity Asset (cua) atom location. No lights setup, no reflection probes, no difficult setting, custom shader or scripting for simple objects.
If you are used to this process, a simple gun from DAZ, exported as .fbx, with 1-3 materials will maybe 5 minutes (plus Unity startup and file handling).
The only real challenge is to re-apply or edit the different materials of an object.
This is something you almost always have to do and somewhat time consumpting for objects with dozens of materials.
I want to encourage everyone to try this out. If you can handle DAZ, you can handle that single Unity scene, too.