Since I’m a MO Jew who went to charedi yeshivos, I have plenty of friends who don’t eat by me, and plenty of friends whose houses I would not eat at. Sometimes accommodations can be made, when friends who keep cholov yisroel come over, we do only cholov yisroel (cold only because of keilim.) If we have someone over for shabbos, we ask about shechita preferences as well as allergies. When I meet friends whose kashrus standards aren’t my own, either they do something similar or we eat out. So far I’ve been dealing this way for years and my parents have been doing the same since before I was born and none of us has lost a friend over it yet.
If you want an extreme example, we once visited one of my father’s non-Jewish friends from college (going back over thirty years). He bought kosher cold cuts, kosher bread, kosher cake, and a new knife all so we could eat there once. Another non-Jewish friend of his has a drawer with three sets of kosher dishes (read 6, milchig plus fleishig) for when his Jewish friends visit.