If the target content is a web app with a manifest, check if the domain is in the list of allowed origins to install said content. If the target content is not a web app, the UA may offer different UX that informs the user that the targ
Not completely sure what you're trying to say with 3 with regard to unmanifested apps. Are you saying that the UA may choose to not install them, or are you saying that the lack of a manifest may mean that certain integrations with the OS may not be possible without a manifest?
Not completely sure what you're trying to say with 3 with regard to unmanifested apps. Are you saying that the UA may choose to not install them, or are you saying that the lack of a manifest may mean that certain integrations with the OS may not be possible without a manifest?