Its weird how the elimist is all, oh, we dont interfere, but they do
Have you read The Ellimist Chronicles? His whole story is laid out as entirely as possible at that point, though he gives enough of a general idea of his motivations throughout his other appearances in the main series. Personally, I would have almost prefered TEC to be its own separate piece of sci-fi and not the central character not be tied in as the Ellimist, because it was a really amazing story that could stand alone anyways and the Ellimist of the Animorphs books was at his coolest when he was at his most mysterious, clever and indirect enough that he could still actually claim 'non-interference' (#7, The Stranger).
I think that the Suspicion was pretty irrelevant. I thought that it was pretty lame, really. I mean, a lot of the story of Animorphs is somewhat believable and most of the aliens are pretty cool, but the Helamacrons were about the dumbest thing in the series so far.
Well, yes it and the Helmacron followup (# 42, The Journey) are pretty irrelevant to the main story-line, but I was OK just because I did enjoy the seamless way the series did manage to integrate and explore other sci-fi/fantasy premises (beyond its own animal shape-shifters premise).
Suspicion's exploration of scale changing perspectives is by no means original (Gulliver's Travels, Alice's Adventures in Wonderland, Honey I Shrunk the Kids are the most popular examples) but manages to bring its own new take on it while still fitting into the Aniverse.
Journey went so far as to have the characters mention what sci-fi it was drawing its inspiration from; again it was pointless to the main story, but it was certainly a neat one as well.
I was amused enough too in the laughable, supreme overconfidence of the ridiculously non-threatening threats of the Helmacrons; yet another trope that isn't original, but managed to take on its own fitting shape in the Ani-verse. Nothing completely new under the sun I suppose.