VScode?

would piping the emulator window to a tab in VS Code be possible with an extension?

Maybe, yes - you could just host the whole Web IDE inside VS code I guess? But using the steps I posted above you can still load files you write with VS code - it's just you don't get the console in the same window.

Is there any guide or something to show how to setup development environment for VSCode?

Not that I'm aware of - but you can use use it as a normal JS editor and then using steps above you just make the IDE upload the file each time it changes