What's the point with that quite lackluster story in Endwalker?

[Lauront]

i'm aware of this and i'm aware that emet-selch indicates he's enthralled in the ENG ver. of shadowbringers and tries to plant a seed of doubt in you that you yourself have been enthralled by the milf crystal which Ardbert even mentions (and then dismisses). generally when i say something like that it's not because i have reason to believe otherwise but because people get -really- upset when you take imply their waifus/husbandos are acting a particular way only because they've been enthralled by zodiark. (emet-selch becomes more jack-sparrow-y, elidibus becomes cold and uncaring, lahabrea is... well. lahabrea. etc.)

It's less a matter of being "upset" in this case. He says he is tempered in the EN version, yes, but not specifically enthralled. In FR he uses the word "subjugated" (presented as that - in quotations), and explains that tempering has made them into energy transmission belts of Zodiark. Up to that point, we might surmise they could still have been acting under his direction. Where it begins to fall apart is the fact that 1) he lacks a will when not being controlled, other than apparently acting on some self-defence instincts; 2) his tempering was due to his great power rather than rites intended to induce slavish obedience and 3) Emet-Selch actively deviates from his original plan by devising for the WoL a test. He even states at the end (with Zodiark gone and presumably "cleansed" through the Aetherial Sea) that his principles remain invincible and that he clashed with the WoL due to their goals being different. He honours the test he set. As for Lahabrea and Elidibus? In their case, yes, tempering did appear to degrade the mind, because they didn't take efforts to preserve their memories (Elidibus) or identity (Lahabrea), unlike Emet-Selch.

It's not that they're tempered which people are disputing, but rather the idea that from this, it follows that they were acting on Zodiark's direction.

i think it's also good to point out that while ancients may have temporarily not suffered that suffering still existed on the star. the (sq)grapes azem supposedly saved was actually done to save the people living on the island which implies both sentient and sapient non-ancients clearly existed on the star at that point.

The source in question gives no reason to believe this.

it's isn't far fetched to then postulate that the lack of suffering the ancients claim to have experienced was no more than just them off-loading their own personal suffering on those they viewed as lesser beings.

I don't get that impression TBH - you might be able to make that argument with Hermes, where he did do just that, but with the rest they appeared to take genuine contentment in working towards betterment of their star and/or for each others' sake.