I'm thinking out loud, please prove me wrong. Addressbook has an delete button, whereas sendcoins has none, as we disable and hide it for the sendcoins page. The same is true for the context menu, the delete entry is ONLY added on the addressbook page and not visible or accessible on sendcoins (we only add it when ``if(tab == SendingTab)``).

So even if the action itself is not disabled, it is not accessible in any way on sendcoins.