I've been using EWL for some time now and I feel as though there is an inconsistency. Some actions, like adding a status message is done via the EwfPage instance and others such as adding a page-level Action is done via EwfUiStatics.
Why aren't all of these similar methods in one place or another? One guess I have is that possibly the methods that are on EwfPage require the instance (and the others are static). But that reason would be refuted by the fact that the property EwfPage.Instance exists, always giving you a static handle on those methods.
EwfPage members can be used on all pages whereas EwfUiStatics members should only be used on Enterprise Web Framework User Interface (EWF UI) pages.