Your comments

I am afraid I am not a WPF expert myself, we've just recently started working on a project where we decided to use WPF for the first time. I wanted to use NLog to log some info to the UI as we are used to, but then I saw there are no targets for WPF controls.

There is already some history with WPF RichTextBox, there is even some NuGet package, but not sure if these solutions still work.

That one is for WinForms, WPF has its own RichTextBox and other common text controls.

I think it would be very useful to have those as WPF is the way to go for C# desktop apps for a long time now instead of WinForms. I am really surprised NLog doesn't support any WPF targets already, quick Google search shows people need it.