Help Sulpiride instead of meto? (SN protocol)

[Lyn]

Though I still can't get metos, I was able to get some Sulpiride.
I've already seen a few discussions here on this topic, but I'm still not sure if it could be an option for SN-induced nausea.

So I'm trying to understand a few things.
And I would be glad if someone could point out any mistakes in the information I found or offer me some advice.
So...

Sulpiride is a substituted benzamide, antipsychotic, and similar to metoclopramide it possesses a pronounced antiemetic activity.

Sulpiride is a selective antagonist of dopamine D2, D3 and to a lesser extent D4 receptors.
And it also acts as 5-HT2A antagonist.
Antagonism at 5-HT2A dominates in doses exceeding 600 mg daily.

And here's what I have learned so far:

• Dopamine antagonists are effective for brain-induced nausea (essentially blocking central nausea pathways).
• 5-HT3 antogonists are effective for nausea and vomiting caused by gastrointestinal irritation, toxic substances, chemotherapy or radiation (it's what meto can do and it might be significant in terms of SN... although @Quarky00 stated:

"5HT3 is not prokinetic, it will reduce vomiting signal but still cause expelling of toxins."

• 5-HT2A antagonists can modulate gastrointestinal function to a small degree. This might help with gastric discomfort or slow digestion, which could contribute to nausea from gastric irritation (definitely not the main factor in terms of SN, but still...).

So I'm trying to understand what kind of nausea typically occurs after taking SN: is it brain-induced (dopamine) or nausea due to gastric irritation (5-HT3A)?
Though I can imagine all of them kicking in at the same time.

Since Sulpiride only starts to act as a 5-HT2A (not 5-HT3A) antagonist, is it viable at all to increase the dosage to 600mg?

Or is it better to stick to the logic suggested by another user:

"meto regimen is 10mg every eight hours a maximum of three times (10mg x 3 = 30mg per day total). We also know that a working stat dose of meto is 30mg as a one-off. Whether this similarly means that their use of a sulpiride regimen (50mg x 3 = 150mg per day total) also suggests a stat dose of 150mg as a one-off might have similar effects would require the expertise of someone more knowledgeable than me."

Or maybe I'm being too anxious and overthinking it since people have succeeded with only SN and nothing else?

Anyway, I'm just trying to figure out if it's even worth using this sulpiride as a substitute for meto.

Any advice would be appreciated!