Makes me wonder if it has something to do with the fact that the protein avenin in oats triggers a gluten-like reaction in some celiacs and that this stricter standard for oat products is concession to those people making noise on that basis.

Yes, but what has really happened is that companies just removed "gluten-free" from their packaging, as General Mills has done for Canadian Cheerios. Why they would allow a 20ppm for gluten-free in other foods and only set this higher level for oats is very odd, and no other countries do this.

That "gut ache" after drinking may be more than alcohol not agreeing with a gut that's trying to heal. Alcohol prevents absorption of vitamins, and actually breaks thiamine Vitamin B 1 so it cannot function.  Thiamine deficiency can cause Gastrointestinal Beriberi, with symptoms of digestive upsets and abdominal pain, nausea, vomiting, anorexia, and can cause neurological problems and problems with thinking and judgement.  I've experienced Gastrointestinal Beriberi myself.  Thiamine supplementation is a must, along with the other B vitamins and Vitamin C.   Gastrointestinal Beriberi and Wernicke's Encephalopathy Triggered by One Session of Heavy Drinking https://pubmed.ncbi.nlm.nih.gov/31543793/ https://pmc.ncbi.nlm.nih.gov/articles/PMC6739701/

Yeah I think my body is definitely telling me to lay off the alcohol I just don’t seem to agree with it right now but that might be because my gut is still trying to heal. 

We are a couple with celiac trying to find a concierge doctor in Palm Beach Gardens/West Palm/ Jupiter area that has knowledge of celiac .  Help!