Excellent analysis of a work that is undoubtedly rich in themes and meanings. I don't know Poe as well as HPL, but the gap between the two is evident, if only for chronological, stylistic, and historical-literary reasons. Poe's horror is something more coherent with the Romantic era, though in his case, it is curiously filtered through the meshes of North American culture, certainly more linked to the sublime and the "free" gothic, or rather reinterpreted according to the sensibility of "pure" New England (though here my old colleague Prof. Guido Carboni would be needed - no, not the coach...).
The firepower, in my opinion superior, of HPL stems from various factors: having surpassed canonical fantasy by framing delirium in an aseptic, materialistic, and scientific approach; for example, he was able to incorporate an autopsy report into a story of pure fantastical delirium (At The Mountains Of Madness), or to "explain" witchcraft rituals with mathematical formulas (The Dream On The Which House). In his frenzied and pessimistic materialism, he nullified the form and substance of his monstrous creations, which can be seen but not photographed.
He historically reconstructed "his" New England and populated it with the most unrestrained and indescribable horrors, surpassing the "old trinkets," as you rightly say, and turning them into toys in the hands of indistinguishable entities. As a revenge for his inability to live in the 20th century, he reduced planet Earth to a determined cosmic contingency, driven more by the capriciousness of "other" entities than by materialistic chance. Contemporary astrophysics and astronomy are discovering influences of currently inexplicable forces, almost metaphysical (black holes, dark matter...) that have determined the balance of our galaxy, and I find it really amusing to think that Lovecraft, a hundred years ago, somehow "intuitively" sensed this.
Hogdosn also demonstrated a mechanistic and "scientific" approach, introducing the fantastical element through abiogenesis (The Derelict, for example...), but as you rightly point out, he achieves aesthetically much weaker results, and his "mania" for maritime adventure often shows its weaknesses.
To conclude this boring rant, I throw in my jab at the usual random interpretations of our intellectuals: inserting Poe into an anthology of the "Cthulhu Mythos" is a possible operation but, in my opinion, extremely forced and unjustifiable; if only because said "Myths" are a made-up construct that has now slipped out of hand. If some commentators, not only local ones, remembered what HPL thought of his own "pantheon" (a wonderfully silly prank devised by him...), perhaps certain curious and often ridiculous statements could be avoided.
Yes, I too managed to escape from myself...