But first, I see there are videos and more about this at https://www.google.com/search?q=ptcl+router+mac+filtering

Now about why MAC filtering is problematic because my Apple Phone has a feature to use a random MAC address for reasons. This is also a setting in Windows 10.

Finally if you think you will set it to only allow specific MAC addresses all versions of Windows that I know of as well as Linux allows us to set out MAC address to the ones allowed.

This setting adds no security.