LightMap Tools will be helpful for you if you use baked lights but you don't have a render farm to build. It allows you to build lights only for the selected level part you are working on.

By setting other actors' Lightmap Resolution to 1 it drastically decreases build time. This way you can quickly iterate and see the result without the need to rebake the entire level.

Video Demonstration:

• Quick Bake - https://youtu.be/-ukS_d4ilRs
• Optimize - https://youtu.be/FkAKhYiblMQ

Features:

•  Quick light bake for a part of your level
•  Tools for editing Lightmap Resolution on your level actors