[Runtime Bug]: Flickering Emissives Portal 2

Edit:

• The described bug was happening with the emissive surfaces tagged as WorldUI. Whilst the commit introduces this issue with the mentioned commit, not tagging the surfaces as WorldUI makes them flicker even on prior commits. Even the runtime version I was using before has this flickering issue when emissives are not WorldUI. Flicker happens when geometry hash changes

Describe the bug

I'm currently in the process of updating my Portal 2 mod so that it uses the latest version of the remix runtime.
Whilst doing that, I've noticed heavy flickering of emissive surfaces. It appears to happen at multiple camera locations, but every time on exactly the same spot. (Maybe surface batching related .. ?)

This is happening on the very latest, unmodified version of the runtime.

I've gone back and tested earlier commits and found that this commit causes the issue:
https://github.com/NVIDIAGameWorks/dxvk-remix/commit/2c5f5388fa75a8feea47d549f64b1084906a4334

Building on the prior commit does not show this issue.

Maybe interesting: turning off NEE Cache or NEE Cache: Enable On First Bounce stops flickering but also reduces emissive influence on the scene

How do you reproduce the bug?

1. Be on commit: https://github.com/NVIDIAGameWorks/dxvk-remix/commit/2c5f5388fa75a8feea47d549f64b1084906a4334

You may need to cherry pick this commit to fix a build issue (at least I had to):
https://github.com/NVIDIAGameWorks/dxvk-remix/commit/e9527448b33bdd9a5e530bb62f548c780384f085

2. Use the portal 2 compatibility mod (without the custom runtime ofc.)
   https://github.com/xoxor4d/p2-rtx/releases/tag/2.1

(I'm in the process to update the release to get rid of dxwrapper usage, will update the link once that's done)

3. Load the game and use console command map sp_a2_bridge_intro (happens on all maps) and notice emissive flicker from ceiling lights

4. Checkout prior commit, build runtime, retest on the same map and notice no flicker

What is the expected behavior?

No response

Version

ToT

Logs

No response

Crash dumps

No response

Media

Video of flicker issue:
https://drive.google.com/file/d/1UAeSeEc-sUywDg9xnvT4PcMsbG-DTVL-/view?usp=sharing

Video without flicker issue on prior commit:
https://drive.google.com/file/d/1zy01i8JNwwbom8bpjuqIkkpYtshpOLu9/view?usp=sharing

Reproduce the flicker in the Portal 2 compatibility mod on map sp_a2_bridge_intro using commit 2c5f5388fa75a8feea47d549f64b1084906a4334, with the noted build-fix cherry-pick if needed. Compare that build with the prior commit and test the NEE Cache settings; done means emissive ceiling lights no longer flicker while emissive influence remains intact.