Blender 4.2 and newer. It is tested on Blender 4.2, 4.5 and 5.2 LTS.

Yes. All materials are image textures and Principled BSDF, so they look right in both engines and can be baked for game engines.

Repeated parts (flanges, valves, railings, cars, panels, insulators) are GPU instances, so even a full refinery stays light in the viewport. Use the Preview detail level while you design and High for the final render.

Yes. Apply as Meshes turns the facility into plain mesh objects with their materials, ready to edit or export to other software.

Yes. Set Condition to Abandoned, or pick one of the abandoned presets: roofs lose sheets, windows break, rust and moss spread, saplings grow and the car parks empty. Every wear effect also has its own slider.