Editing manifest.webmanifest

That is not possible at the moment, unless you overwrite this method in a custom plugin.

The plan is to make this configurable by site admins, but I’m waiting for this bug to be fixed by the chromium team before working on that: https://bugs.chromium.org/p/chromium/issues/detail?id=1091612&q=component%3AUI>Browser>WebAppInstalls&can=5.