The implementation that backs many IndexOfAny searches with SearchValues today only leverages Vector128/256:
https://github.com/dotnet/runtime/blob/a5461cbc8ed20e0981fd4e846a180f35b07dcc0a/src/libraries/System.Private.CoreLib/src/System/SearchValues/IndexOfAnyAsciiSearcher.cs
We should teach it about Vector512.

(@MihaZupan has a prototype.)