Improving sharpness of reflected water caustics

I am using PDS (Photon Difference Scattering) for highest quality reflected water caustics.
Using a Spotlight as light source with caustics enabled.
Unfortunately, even when using a caustic light map resolution of 4096 my results are quite blurry.
And if I try increasing my caustic map resolution to 8k I always crash the editor! (see attached error)

If I use Procedural Caustic Mesh instead, the results are more realistic in terms of sharpness but PCM results in a lot of visual artifacts and glitching.

Hopefully one of the engineers will read this and be able to offer a solution.
Is there some cVar or setting that might help me achieve sharper results?
Attaching screen shot.


8k_error

Update - discovered I can go as high as 8000x8000 in my caustics map resolution without crashing. This helps but if there are any other settings I should try please let me know!

Hi @bach44 ,if you downloaded the demo project, I think there is a blueprint called BP_RTX under content folder, you can directly use very high setting which is recommended for realtime game purpose, you can switch to the film preset if your project is more close to offline rendering quality. For your scenario, PCM is recommended to use , it may introduce some over-bright pixels, but you can tweak r.RayTracing.WaterCaustics.EpsilonArea with some small float value to eliminate this artifact. Cheers !