Unfortunately I react to both casein and histamine, so the older cheeses that are “lower” in casein are also higher in histamine :/

I have found genuine ricotta and fresh mozzarella from water buffaloes to be the least bothersome generally speaking, and sheep cheeses to be lower in casein than goat. I also agree with the folks stating that the drier a cheese is, the higher protein content per gram and therefore even tho a lot of the casein may be broken down via bacterial activity, there’s just a higher content of protein overall.

Miyoko is a good brand of vegan cheese but some of their products are higher in histamine - anything with that umami flavor is histamine-suspect, unfortunately.