I followed the instructions here for setting up a wpf host, but the app starts without ever loading my code. I also tried to get WASM debugging to work with no success. That said, I'd rather have a wpf host if possible since I think that will have a faster/smoother debugging and development experience.
No, Uno.UI.WpfHost is no longer maintained.
There's currently no one perfect solution for debugging on Uno-WebAssembly; the debugger is temperamental, as you've noticed, and limited even when it does work. One option is to add a Skia head to your project (Linux and/or WPF), for which the debugging experience is very good and the comportment of Uno is close to that on WebAssembly.