This issue is to track limitations of PowerShell Core 6.0.0 on the macOS platform. Limitations being defined as features that are already included in pwsh but either do not work at all or work partially on macOS (probably due to CoreFX limitations).

• Web Cmdlet Client Certificate Authentication Support Client Certificate Authentication in WebCmdlets Unavailable for macOS #4650
• Web Cmdlet Multiple -SslProtocol Support Add SslProtocol Support to WebCmdlets #5329

Please update with more if you are aware of them.