C# bool is not Blittable. Instead, use byte or wrap byte to offer BlittableBool.

README.md

README

• see C# doc: https://learn.microsoft.com/en-us/dotnet/framework/interop/blittable-and-non-blittable-types
• Reddit: https://www.reddit.com/r/dotnet/comments/swcjll/a_boolean_is_4_bytes_unless_its_in_an_array_in/

BlittableBool.cs

public struct BlittableBool
{
    public readonly byte Value;

    public BlittableBool(byte value)
    {
        Value = value;
    }

    public BlittableBool(bool value)
    {
        Value = value ? (byte)1 : (byte)0;
    }

    public static implicit operator bool(BlittableBool bb)
    {
        return bb.Value != 0;
    }

    public static implicit operator BlittableBool(bool b)
    {
        return new BlittableBool(b);
    }
}