It looks like .NET Core 3 supports hardware intrinsics and has support for CRC32C:
https://github.com/dotnet/designs/blob/master/accepted/platform-intrinsics.md

_mm_crc32_u64
https://github.com/dotnet/coreclr/blob/master/src/System.Private.CoreLib/shared/System/Runtime/Intrinsics/X86/Sse42.cs

Would be great if the library could use this eventually when the instructions are present on the right platform.