Maui TabbedRenderer (iOS) with custom property

i have a custom TabbedPage with an additional property. Like this:

public class CustomTabbedPage : Microsoft.Maui.Controls.TabbedPage {
        public static readonly BindableProperty SeparatorLineColorProperty = BindableProperty.Create(nameof(SeparatorLineColor),
           typeof(Color), typeof(CustomTabbedPage), null, defaultBindingMode: BindingMode.Default);

        public Color SeparatorLineColor {
            set => SetValue(SeparatorLineColorProperty, value);
            get => (Color)GetValue(SeparatorLineColorProperty);
        }
}

In the docs: https://learn.microsoft.com/en-us/dotnet/maui/user-interface/handlers/?view=net-maui-8.0#page-handlers it is mentioned that TabbedPage handlers are TabbedRenderer in iOS and android. So i created in a partial class in iOS platform folder:

public partial class TabbedPageHandler : Microsoft.Maui.Controls.Handlers.Compatibility.TabbedRenderer{
    private static void MapSeparatorLineColor(TabbedRenderer renderer, TabbedPage page) {
        //Test
    }
}

and in a partial class for the property mapper:

public partial class TabbedPageHandler {
        public static PropertyMapper<CustomTabbedPage, TabbedPageHandler> PropertyMapper = new PropertyMapper<CustomTabbedPage, TabbedPageHandler>(Mapper) {        
            [nameof(CustomTabbedPage.SeparatorLineColor)] = MapSeparatorLineColor,
        };
        public TabbedPageHandler() : base(PropertyMapper) { //Error
        }
}

The problem is, that the Microsoft.Maui.Controls.Handlers.Compatibility.TabbedRenderer has no constructor for the mapped properties, but the static Mapper field exists in TabbedRenderer.

I tried to add my custom property in a static constructor:

    public partial class TabbedPageHandler {
        static TabbedPageHandler() {
            Mapper.Add(nameof(CustomTabbedPage.SeparatorLineColor), MapSeparatorLineColor);
        }



        //public static PropertyMapper<CustomTabbedPage, TabbedPageHandler> PropertyMapper = new PropertyMapper<CustomTabbedPage, TabbedPageHandler>(Mapper) {      
        //  [nameof(CustomTabbedPage.SeparatorLineColor)] = MapSeparatorLineColor,
        //};

        //public TabbedPageHandler() : base(PropertyMapper) {
        //}
    }

This works, but i have doubts this is the correct implementation. What is the correct way to map my custom property? I have expected that this works like entrys and the constructor from the base class takes my custom properties.

An issue is open at github: https://github.com/dotnet/maui/issues/19998. There is also a workaround. I think the MAUI-Team will fix it sometimes.