The Lumen documentation states it's a "fully dynamic global illumination and reflections system that is designed for next-generation (current gen now) consoles" - so no baked lighting with Lumen. If you want to use baked lighting you would have to setup your project accordingly. The question whether Lumen is optimized for…
well fortnite has the epic team behind it so they have a bit more firepower than a solo-developer. but it looks like you can include lumen in quality settings for your game: https://docs.unrealengine.com/5.2/en-US/lumen-performance-guide-for-unreal-engine/ the game user settings has a benchmark node that you can run to…
Using entirely stationary/dynamic lights is not that unusual for a game, and hasn't been for a while. Open-world games practically require it. I think lumen is probably a bit immature at the moment, Fortnite notwithstanding with first-party support from Epic. However given the typical development cycle time I absolutely do…