MobileHDR is not supported on Quest, and not a solution.
When you’re working in-editor you’re not using the same renderer as the Vulkan Forward renderer that’s used on Quest. Use Editor Preview Level and set it to Android Vulkan to simulate what your content will look like on Quest when working in-editor.
If you don’t need bloom, one way would be to tint the emissive color toward white to simulate overbrightening. You could also try setting up gradients where the edges of the emissive areas are more saturated.
You should extract it to the Plugins folder inside your project. It has code in it, so you’ll also need to build it. It should automatically get built if you convert the project into a C++ project.