Thank you for reporting a bug to Unity.
We have reviewed the issue carefully, and in this case, the team is unable to prioritize fixing this bug. There are a number of reasons we make this decision, including the impact and severity of the issue across our user and customer base, and the possibility that future plans may solve the problem in a different way, or that a workaround for the bug may be available.
As a reminder, Streaming Virtual Texturing is currently marked as an experimental feature in documentation, but we greatly appreciate the feedback you provided. As a result of your feedback, we made plans to document this limitation more clearly in the user manual page for Streaming Virtual Texturing.
While investigating your report, we verified a potential workaround for this use case may give the behavior that is intended: using Streaming Virtual Texturing textures in materials that use alpha-clipping. The potential workaround is to create a custom MonoBehaviour that uses the (experimental) Streaming.RequestRegion API, then add this component on those object(s) using alpha-clipping with Streaming Virtual Texturing. Some sample code is already provided in the Scripting API documentation for that experimental C# API and can be used as a starting point to create your own script. For more info, see: https://docs.unity3d.com/ScriptReference/Rendering.VirtualTexturing.Streaming.RequestRegion.html
A different approach - where a monobehaviour toggles the Alpha Clip OFF to trigger texture streaming initially, then later toggles alpha clip ON for rendering - proved to have significant limitations when we tested it.
Today we will be closing this case. Thank you again for taking the time to report this issue, and please let us know if there is anything else that changes the impact or severity of this issue.