I recently had the opportunity to help create a Megascans assembly pack for the new Mega Assembly workflow. With this new workflow you can utilize these optimized game ready assemblies to build out an environment in minutes!
I made the assemblies for this pack, while Cordell Felix did polishing, optimization, set dressing the environment, lighting, and post processing.
Special thanks to Cordell Felix. He built the pipeline for these packs, helped to get the team into a game ready mindset rather than a strictly cinematic one, and he was a tremendous help in getting this pack to ship. Check out his post here: https://www.artstation.com/artwork/R34GqW
Here's where you can grab the pack! https://www.unrealengine.com/marketplace/en-US/product/lava-field-collections