Bug Broken asset and material previews

I really have no idea why isn't unity focusing on this, Ever since the release of HDRP preview of assets has been broken, Material preview often shows nothing more than a glowing sphere or doesn't show at all.
Even prefab previews are completely broken, most of the time they show pink previews, and other times they are not the right exposure values.

After using Unreal for a while and then switching back to unity it's just very irritating to drag and drop every item into the scene or open assets in prefab mode to get proper previews.

PS: Even till now (HDRP 12) unity's default values for post-processing and color curves are far from matching what unreal has by default, overexposed parts present in most of the default scenarios.

 

I'm using the latest alpha 2021.2.0a19 and HDRP 12

 

Also, there are a few more things I would like to ask if that could be potentially integrated into asset/Material previews:

• The ability to customize the Prefab preview scene has been there for some time now, but it would be really helpful if we could use that or some other scene inside asset preview as well. It can be a great alternative to a full-blown Look dev window. At least add an option to control exposure for assets that have emissive surfaces.
• In all the versions of HDRP I've worked with including 2020.3 LTS the reflection probe field for material previews has been broken, it doesn't really do anything right now. So, it would be helpful to fix that as well as an additional option to use HDRI's instead. Because currently, it doesn't have any kind of exposure slide so even if the reflection probe option worked, it would be overexposed or underexposed in most cases.
• Support for using custom mesh inside material previews.
• Support for using environments like Look Dev has inside Material previews.
• If you could maybe add support for using a custom scene with a variation for different lighting setups then it would be the best option, as currently we just have a two/one light mode in the material preview. If we were using a scene then we could use custom post-processing to evaluate the material without having to open a Look Dev window every time.
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• If the above preview could be what I see with maybe an API to adjust the light's and ground plane's position according to the object's bounds then it would be awesome.
• Add support for material preview in look Dev with custom mesh instead of saving a new prefab every time for previewing it.

For look Dev:

• Improve look dev with the option actually adjust the intensity of directional light
• Adjust camera exposure instead of just brightening the HDRI. But this only works if I can control the intensity of directional light independent of the Environment when needed. ( I have a good example for it if it doesn't seem worthwhile to you)
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• As you can see that For the second screenshot it would have been nice to have some more control.

 

This would be helpful for prefab previews as well btw

 

Prefab previews are broken in URP also, most of the time the only thing that fixes this is deleting the library folder. At this point, this has been happening for over 2 years. Will we ever get a permanent fix?