Does Apple provide a correct specification for implementing overflow scrolling on custom window controls? Or is a default behavior that only Apple-blessed graph

Does Apple provide a correct specification for implementing overflow scrolling on custom window controls? Or is a default behavior that only Apple-blessed graphic components have? Failing to follow the Apple guidelines would be bad for Firefox. If the issue is not having a spec, we'd be talking about Apple actively sabotaging apps like Firefox. I'm a Firefox user on macOS and I don't remember issues with scrolling. I don't use a trackpad, maybe that's the issue?