As distillation continues the concentration of methanol drops.
The highest concentration is at the start. This is also generally full of undesirable flavours.
People also forget that ethanol competitively inhibits metabolism of methanol in a way that protects healthy adults from toxicity.
A safe alcoholic drink can have methanol in it, iirc it's about 80:1 ethanol:methanol by EU rules. And generally considered tolerable [0].
What is actually toxic is much higher ratios of methanol than that.
Unless you have severely f'd up your fermentables you shouldn't even have that much methanol in the starter!
This is why everyone is disagreeing with the safety in this thread.
It's also why people wonder why so many tourist destinations have been mixing methanol into alcoholic drinks. They probably could serve drunk people high concentrations relying on ethanol already in their blood and follow up drinks to stop noticeable harm.
Probably most adults could drink 5-10% methanol (if ethanol is about 50%) and never notice the toxicity.
As opposed to the crowd sobering up and leaving.
But also I believe the bar (staff) often genuinely don't know what their serving is harmful.
I should have added the limit to safety at low levels of methanol is actually that your body processes ethanol much faster than methanol. So it's more that the crowd goes home and then hours later (once ethanol has been cleared) the methanol finally is picked up by the enzymes that makes it toxic. If they stay drunk (on ethanol) for days the methanol might have been excreted before being toxified.
So maybe the answer is water down the shots of your obviously drunk customers.
TBH, I also had to do my own bit of googling because I barely drink alcohol to begin with, but it does look like "at the start", it's not very distinguishable from ethanol in taste and in effect.
Whatever subtle differences exist between them are probably unnoticeable to people who are already drunk, not to mention drinking cocktails with all sorts of other flavors mixed in.