I was the original reporter of this issue, however it isn't really an issue.

The reason WPF's DataTrigger seemed to be different was that Noesis.GUI.Extensions was referencing an unofficial Interactivity/Behaviours Nuget package, which was built against code from 2012.

The DataTrigger in Microsoft's official Microsoft.Xaml.Behaviors.Wpf Nuget package (https://github.com/microsoft/XamlBehaviorsWpf/blob/302a27da21749b330a8b5807bc69f62f4372ff94/src/Microsoft.Xaml.Behaviors/Core/DataTrigger.cs) does invoke the evaluation the bindings in the OnAttached method:

    protected override void OnAttached()
    {
        base.OnAttached();

        //fixes issue #11. We want to evaluate the binding's initial value when the element is first loaded
        if (AssociatedObject is FrameworkElement element)
        {
            element.Loaded += OnElementLoaded;
        }
    }

With the latest version of our extensions (3.0.8) we moved to the official Microsoft.Behaviors.Wpf so both implementations should match.