I am curious about the context you mention. The button itself, as far as I know has only one case when the context is specific. That is if you are on the homesc

I am curious about the context you mention. The button itself, as far as I know has only one case when the context is specific. That is if you are on the homescreen, but not on the first page, a single click will bring you to the home page. Otherwise it will bring you to the last page you have been on. The camera/music controls are linked with the control center but that is operated differently. Double tapping is definitely a weird choice for accessibility. Also, you can also triple click the home button as an accessibility shortcut. But it has to be enabled.