Could you make an app that just installs your web app in the launcher so the user only uses your webapp directly? iirc that can't be pulled as easily by Google.
I found it harder to make a clean, smooth user interface. Lots of workarounds to make things fit into the right place, to make the right thing in focus for user input. I'm not a professional front-end developer so maybe I just wasn't any good at it, but achieving a basic level of quality was much harder.
