Cetshwayo's visit to Queen Victoria, the Jameson Raid and the rinderpest, Bobs and Oom Paul, and even King Shaka are all in there somehow and to some end, and Cheng too uses her unravelling to great effect. We are indeed asked by Joyce to enjoy more than his syntax and symmetry. A tale that was tolled. But my spot-check of 17 standard cribs on the Joycean performance reveals that imperialism is indexed in not even one. Oh, for a Joycean parody.
Books are too expensive for that and repetition can undermine a fine, firm argument.