Ah, I see. So, it appears your surface cache representation is at least capturing the trunk and some of the leaves, but the pink would mean that all those areas have no coverage and wouldn’t bounce light outside of screen-space.
What direct shadowing method are you using? Given the high-frequency detail, I’d heavily reccomend using either VSMs or RT shadows, as any other method is likely to not give sufficient detail for things to shadow correctly, which could be part of your problem. I’d raise that to epic and test.
I’m also noticing that your reflections are set to medium. That means lumen reflections are not enabled, which would mean specular surfaces would light-leak and your reflections quality will generally be quite poor. I’d bring that setting up to high or epic as well and see what it does for you.
As a general rule for a quality-first approach, you should ‘bracket’ your scalability. Basically, try everything on the lowest settings to understand how it looks, then try everything on the highest (or epic) settings to understand what the best visuals look like, and then selectively work backwards from epic, lowering settings and gauging your result, until you can find what gives the best visuals for the acceptable performance.