C# Use .NET Span/ReadOnlySpan
Span is an alternative to Stream but allocation free.
It is useful for high performance code.
Since Kaitai simply reads and interprets bytes , it can be easily achievable with Span making code more efficient.

https://docs.microsoft.com/en-us/archive/msdn-magazine/2018/january/csharp-all-about-span-exploring-a-new-net-mainstay