Hi Samantha:
I am sorry you are going through this, as I know it is not fun at all. You do not mention whether or not you've been thoroughly checked out by a Cardiologist or Electrophysiologist, but I will assume you have and that's good.
I have not noticed any particular foods to cause PVCs, but I am not surprised by your observation that foods high in tyramine can trigger them for you. Tyramine, I think is an amino acid, and it can also trigger migraine headaches, so it obviously has a neuro "toxic" effect for some people. It's great you've identified this!
What I do notice is more of a "mechanical" and a "timing" issue in terms of triggering irregular beats. For example, if I over-eat and have abdominal bloating, I can notice more irregular beats, including PVCs. Some foods cause me to bloat at this menopausal stage of life, so I avoid dairy, greasy foods and foods high in sugar. And, speaking of sugar, I can also identify periods of more irregular heartbeats after ingesting larger than usual amounts of carbohydrates, especially on an empty stomach! Think bread before dinner or a bad-for-you treat in the middle of the afternoon. Not only will the resultant rise in blood sugar cause PVCs for me, but then I will be bloated later as well, and the PVCs can continue for several hours. So this is all manageable, for the most part. I just make sure to eat some kind of protein with any carb that I might eat (save the dinner roll or cornbread to eat with dinner, not before dinner), eat less of it (like, treat myself to half or a smaller portion) and never eat a cookie or scone or something carb and high in sugar on an empty stomach.
Now, when this happens, my trick is to go for a walk. In the summer, when it's hot, if I have to, I'll go run an errands to a large department store or Costco or grocery store and move, move, move to make my digestion speed up. And that leads me to the last point and that is, if you are medially cleared to do so, the best thing you can do is to get some exercise every, single day or at least 5 days a week that causes your heart rate to increase. It does not have to be an all out, high intensity workout, but steady and regular. I find that when I back off from this for weeks at a time, my PVCs can creep up again. Hope this is helpful to you and I would love to know how the extra potassium works out for you! Good luck.