After you get to the point where it costs 6 energy each try, yes then greeting is better. But he's not that bad actually, so in the beginning you can just try the Amity game.
I managed to get 304 with 96 before I started to wave at him

{Disclaimer: not an exact translation but matched to the NA knowledge database}

For Sparking Interest

1) After Death
2) Will of Elion
3) Birth of Faith
4) Evil Gods in Darkness
5) Tower of Will
6) Dragon Watcher

or

1. Will Of Elion
2. Dragon Watcher
3. Birth Of Faith
4. Evil Gods in Darkness
5. Tower Of Will
6. Bell Ringing from the City

For Failure to Spark Interest (Для провала интереса)

1) Road of Repentance
2) Bell Ringing from the City
3) An Elionian Definition of Heresy
4) Evil Gods in Darkness
5) After Death
6) Tower of Will

[Open of translator notes]

the better fail stack order (at least in NA) is

1) Tower of will
2) An Elionian Definition of Heresy
3) Evil Gods in Darkness
4) Bell Ringing from the City
5) After Death
6) Road of repentance

или

1) Башня сильной воли
2) Методы инквизиции Эллиан
3) Тени злых богов
4) Звон колоколов
5) После смерти
6) Путь покаяния

[Close of translator notes]

Failure rates are random, Buffs of interest increase don't exist.

The 5th and 6th points may not proc

Amity points +8/+27/+53

Accumulated favor 77-93
minimum Favor 33-37

You won't be able to spark interest 3-5 times when asked, therefore, when possible skip these requirements, don't do requirements where the first requirement requires 70+ accumulated favor or minimum favor of 25 ( since the 5 and/or 6 knowledges may not proc)
The best option begins with the requirement "speak with..." [talk freely]
Consider that for each skipped requirement (amity game) you lose energy the higher your amity, the more energy is required 4/6/8..., and choose what's most profitable for you, attempt to get ~50 points (amity) of friendship or wave with amity buffs popped.

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
If Waving, do so with the
1) Improved Elixer of Amity +30%,
2) pickled fish +5% and
3) Calpheon Noble Suit/Dress +15%,
and you will get +4 Amity per 3 energy
^^^^^^^^^^^^^^^^^^^^^^^^^^^
{Translator's Opinion ^this is the best method^}

Be aware that this isn't a 100% foolproof method for raising Amity with the given NPC, it's possible that he will like all the knowledge, but you may not achieve the required Favor and will receive +0 on 2 or 3 attempts
My recommendation/advice, end the conversation after the first round, as in roughly 70% of situations you won't make it to the end, this way you will receive more Amity points than for just greeting up to the point of 400 amity (friendship), past that it's better to wave.

The NPC also has 2 Quests (tasks) which give 30 amity as a reward.

Ethinicity I / Ethnicity l / Ethnicity 1

Knowledge Khuruto's https://bdocodex.com/th/theme/6638/