Native views and VS2017 intellisense not working

Today I found out about Native Views, awesome!
However, my intellisense is not working for this. It works fine except for inside the native xaml.

My xmlns declarations:

xmlns:ios="clr-namespace:UIKit;assembly=Xamarin.iOS;targetPlatform=iOS"
xmlns:androidWidget="clr-namespace:Android.Widget;assembly=Mono.Android;targetPlatform=Android"
xmlns:formsAndroid="clr-namespace:Xamarin.Forms;assembly=Xamarin.Forms.Platform.Android;targetPlatform=Android"
xmlns:win="clr-namespace:Windows.UI.Xaml.Controls;assembly=Windows, Version=255.255.255.255, Culture=neutral, PublicKeyToken=null, ContentType=WindowsRuntime;targetPlatform=Windows"

My xaml controls:

<ios:UISwitch On="{Binding Path=IsSwitchOn, Mode=TwoWay, UpdateSourceEventName=ValueChanged}"
                    OnTintColor="{x:Static ios:UIColor.Red}"
                    ThumbTintColor="{x:Static ios:UIColor.Blue}" />
<androidWidget:Switch x:Arguments="{x:Static formsAndroid:Forms.Context}"
                            Checked="{Binding Path=IsSwitchOn, Mode=TwoWay, UpdateSourceEventName=CheckedChange}"
                            Text="Enable Entry?" />
<win:ToggleSwitch Header="Enable Entry?"
                        OffContent="No"
                        OnContent="Yes"
                        IsOn="{Binding IsSwitchOn, Mode=TwoWay, UpdateSourceEventName=Toggled}" />

Intellisense stops after <ios: and the other platforms. It seems it can see the xmlns but not what's inside.

When I run the app it works great, I get different controls for each platform.
Im using VS2017, 15.3.4 and tested Xamarin.Forms 2.3.4.270 / 2.4.0.269-pre2 (nuget).

Anyone else experiencing this? Or is this just not supported?