The autobiographical constraints that had characterised all Joyce's fiction before now were now loosened to include all history, with all Irish history especially favored.
Remarkably, as if purified by isolation, the characters in these earliest vignettes have almost no parents, no children, no siblings, no spouses.
The first depiction of Tristan and Isolde is hyperstereotyped, with only the faintest autobiographical echoes in the first section. (Issy has faint traces of Nora, Tristan has traces of Jim and Gogarty and maybe Stannie and others. Bloom and Molly are also hinted.) The abandoned section seems plausibly a parody of JAJ and NB's real relationship problems.
(Why else would T&I open with a somewhat heavyhanded application of a measurement motif, demonstrating phony/shallow 'perfection', except to emphasize that he's illustrating a pure stereotype?)
Roderick O'Connor, as a rare exception, is portrayed neither autobiographically nor historically-- his circular heeltapping is purely Joyce's symbolic dream-imagination as far as we know. (Take as startingpoint any sad drunk drinking any lone other's dregs, then amplify it to everyone else's, then make him the bartender, and then make him a king...) (Maybe Joyce had once watched his father do this???)
(Were Vico and Bruno really shaping Joyce's earliest choices in some way at this point? Where's all the shadow-twin stuff from the notes?)
Kevin is recognisably Stannie, incarnating sterile/cowardly retreat, false purity. Issy's childhood is diverse, but surely has echoes of Nora and Lucia. (The broth joke, remarkably, gets transferred from Issy to Kevineen.) (Kevineen mentions mother and sisters.)
Mamalujo are (barely) AE&co, with wildly exaggerated senility and sterility. Their eventual song is notably fourfold, as JAJ explained to HSW, but their four compasspoints aren't notably viconian. (They have divorced spouses.)
Berkeley and Patrick are maybe James and Stannie or James and any other antagonists. (Ditto, years later, for the Muddest Thick...?!)
HCE and the cad are everybody, universalised...? Starting with Joyce himself in Paris, and Parnell...
The Shem/Shaun brother-duality seems to evolve from a sinful-HCE/virtuous-Tristan generational duality.
If the Letter is an iconic symbol of all books, shouldn't it primarily reflect Ulysses, and Finnegans Wake itself? (why does ALP get to be the lone speaker?)
(Even Bloom's adventures in Ulysses were seriously constrained by the requirements of the Homeric parallel, filtered through Joyce's 1904 experiences. An artificial intelligence given the same constraints could have generated a very similar solution. But what could possibly lead it to ROC?!? ...Take a topmost-er, and reduce him to the lowest imaginable point? And T&I: take the most perfect romantic stereotype...)