I did something similar on Windows by creating a "virtual desktop," where I can give the app focus without stealing it from another one. The idea was to basically reimplement RemoteApp without needing a dedicated Windows server. However, in that case, the app is not visible to the user unless you use "connect" to the virtual desktop; to do it, I implemented (WIP) a simple VNC server in C#.

Thanks! We haven't gone deep on Windows yet because we're still focused on polishing the macOS release. We want to go deeper on the Mac experience before going broader across platforms, and there are still a lot of features we want to ship and use cases we want to share.