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

[Absimiliard]

How does one prove something is different in another language? Me showing you the original JP text and following it up with a translation isn't going to verify anything for you unless you can already read Japanese. Therein lies the problem. But for the heck of it, here you go:

Hythlodaeus
"Don't be nervous.
The white robe that Venes-sama is entwined with,
Evidence of a fair "unstained person"

Hythlodaeus
"Those who have retired from official positions such as the Committee of Fourteen and still live,
A sign of an adviser that only Elidibus the Arbiter can tangle.
I'm sure your story will be taken seriously."

Venes-sama of course being Venat. Note firstly this clearly says the white robe is not limited to Convocation members. Note also the mention of it representing an advisory position, one which Elidibus seemingly must bestow or take away. I would also point out the phrase of a "fair and "unstained person." As I said before, we can infer the Convocation considers these individuals to be trustworthy and upstanding, elsewise they would not be granted that position, but that is not the meaning of the position so much as a requirement thereof. Nor would such a position protect someone from needing to prove their arguments.

[RobynDaBank]

How does one prove something is different in another language? Me showing you the original JP text and following it up with a translation isn't going to verify anything for you unless you can already read Japanese. Therein lies the problem.

I can read a little bit, actually. Can try if you'd like?

[Absimiliard]

I can read a little bit, actually. Can try if you'd like?

ヒュトロダエウス
緊張せずとも大丈夫だよ。
ヴェーネス様が縺っている白いローブは、
公正なる「染まらぬ者」の証・・・・・
ヒュトロダエウス
十四人委員会を筆頭とする公的な役職を下りてなお生きる者と、
調停者エリディブスのみが縺える、助言者の印さ。
キミの話も、しっかり受け止めてくれると思うよ。

You could also get:

Hythlodaeus
"Don't be nervous, it's all right.
The white robe that Master Veness is entwined with is the
The sign of the fair "undyed one""

Hythlodaeus
"A sign of counsel, which only a man who has left his official post, headed by the Committee of Fourteen, and a man who is still alive, and who is not a member of the Committee of Fourteen, can bear.
And only the mediator Elidibus can be a sign of counsel.
I'm sure they'll take you up on your offer."