We encountered significant memory allocations and GC pressure when writing multiple classes containing integer/double with the C# driver. I have tested version 3.4-3.6, and each have this issue.

These allocations occur as byte array allocations, from ByteBufferStream.WriteDouble and ByteBufferStream.WriteInt64
The below is from Visual Studio 2026 Object Allocation Profiling, running .NET 10

I noticed there exists a _temp array that exists in ByteBufferStream, that is used in other areas of reading/writing (Eg: WriteInt32), and had the thought if it possible to reuse in those areas aswell, as the data is under 12 bytes.

I assume this is conceptually similar to issue 5531 / GitHub PR 1670