RxUi | pure functional concept of talking to Android View layer | Reactive Programming library

I'm trying to learn ReactiveUI. Currently I'm playing with ReactiveUI.Validation.

I'm using a simple TextBox. Everything is working as expected if the binding doesn't have UpdateSourceTrigger=PropertyChanged. If i add it, it will hang when i type something in the textbox. What do I miss?

Here is the MainWindow not working code:

I have a list of rectangles that I want to display on a canvas. I used Krzysztof Skowronek's answer to this question, but he doesn't use ReactiveUI Binding; I am. But I can't get any of my rectangles to show up on my canvas. Everything compiles with no errors and there are no exceptions being thrown. There's not much to this code because I created a new project just to test this out before adding it to my actual project. Here's what I got.

MainWindowViewModel.cs

I've been testing ReactiveUI for a while now (highly recommend it!) but recently came across a performance issue that I'm not sure if it's due to ReactiveUI itself (given that it seems to rely on reflection for some things) OR the Xamarin.Forms App Shell. There's a distinct delay when changing to a Tab whose content has ReactiveUI bindings, this is more noticeable when running on an emulator but can also be experienced on a real device too (tested on Android 6 and Android 9 devices). Is there a strategy to improve App Shell tab performance? The performance issue is only on the tab's first load. Relevant code below (simplified example based on base App Shell visual studio template):

AppShell.Xaml

I am trying to get my head around with ReactiveUI. I created a new project with the following main packages:

1. Xamarin.Forms 4.1.0.618606
2. PropertyChanged.Fody 3.0.1
3. ReactiveUI 9.19.5
4. ReactiveUI.XamForms 9.19.5

The project have a page with associated viewmodel. I want to Bind View with the ViewModel using ReactiveUI. But the binding does not work. The project build and run but does not fire any property changed notification neither any command. The app needs to display a list of company names. But the list does not display the collection defined in ViewModel . The app should allows the user the sort the list with CollectionChangeCommand with every change in search query.

The View Code :

I am just starting to use ReactiveUI for my Xamarin Android and iOS projects. I noticed that my Android fragment that uses ReactiveUI takes a long time to load initially. For example when calling ReactiveCommand.Create for the very first time in my app, it takes about 250 milliseconds. Similar thing when calling the OneWayBind, WhenAny, BindCommand for the first time. But if I re-instantiate the view and view model again these methods return almost immediately ( < 3 ms).

I'm relatively new to ReactiveUI and I'm trying to asynchronously execute a database query from a ReactiveCommand. From what I can tell, the problem isn't with executing the async query, but when I try to load the results into a ReactiveList in my view model. I believe that this is a scheduling issue but I'm not familiar enough with RxUI to come up with the correct approach.

I've tried subscribing to the command in the view model using ObserveOn with both RxApp.TaskPoolScheduler and RxApp.MainThreadScheduler but neither seems to help.

My view model:

Caveat:
Brand new to ReactiveUI. Trying to go full on RxUI with the intention of never setting a view's DataContext. I believe this can be done!

Scenario:
I have a button and the button has a style and that button's style has a MultiDataTrigger with first condition being IsMouseOver and second condition being a property on my ViewModel of type bool. This then changes the background or foreground of the button. Traditionally, you would just bind that second condition to the ViewModel's property.

Is there a feasible way for this interaction to work without using a DataContext yet still have the same outcome I expect? I can't directly access the condition binding since it doesn't have a name. So there has to be some weird setup to get this to work.

Solution not really a fan of:
I could potentially add a control that isn't visible, give it a name, and use the this.OneWayBind() to bind that property to the "IsEnabled" property of this control. In doing so, my second condition of the button's MultiDataTrigger could then use binding based on ElementName and its path of IsEnabled. This would allow me to NOT use a DataContext but seems way too "hacky" for my taste. There's gotta be another way!

Thanks in advance!

Edit 1 - Attempt 1 based off Glenn Watson's comment to the post

I'm trying to add RoutedViewHost to my View:

I'm using the excellent dynamicdata for bridging my data layer to my UI (using RxUI). The dynamic data part boils down to the following typical piece of code. There is a SourceCache of ItemViewModels ("_sourceCache") which gets bound to a ReactiveList of ItemViewModels ("Models") which in turn (in the View) is bound as a ListView.ItemsSource: