How to illuminate a really tall tower level

Dear Unreal Wizards,

I am currently working on a project with a really high tower level (3d jump king / Only up - like)

My level design is very dense so as one can imagine the bottom part of the tower is very dark/black because of the shadows coming from above.

The best visual result I have achieved so far is with two directional lights (one casting shadows, the other does not). Performance wise it isn’t the greatest either as one can imagine so I was trying to figure out a more elegant solution.

Baked lighting produced very mixed results, so I’m currently using Lumen. Very high indirect lighting intensity sort of increases the brightness, but seems to produce a lot of artifacts/flickering.

I have messed around with post process volume settings (especially shadow contrast) with some mixed results (areas without anything above (no shadows) are way too bright.

I’m open for suggestions. Thank you in advance