What do you see an app doing that the mobile site doesn't currently do? Most mobiles (iPhone/Android) have an option to create a home screen shortcut to a website so it looks like an app but just opens the browser. I've done with on my Pixel 2 so I can quickly jump onto the site :)
I'm afraid that value cannot be edited, it will always pick up the last file downloaded by the user. It's good feedback though, we should probably look at how it works and improve it for future releases.