• .WithLabels() & similar now accept ReadOnlyMemory as alternative to string[]. Same behavior, just easier to use if you already have a ReadOnlyMemory.
• .WithLabels() & similar now accept ReadOnlySpan as alternative to string[]. This enables allocation-free metric instance creation if a metric instance with these labels is already known.
• Incorporated various optimizations to reduce the required CPU time and allocated memory, including #410, #443 and other contributions.
• Observation of large histograms is now 10-30% faster on machines that support AVX2 instructions.
• health checks exposed via ForwardToPrometheus() no longer create a default metric if a custom metric is provided #444