the slower reaction I would think is a good thing....
I introduced goat's milk into my diet when dd2 was 6 mos old, and she was fine. We just introduced it to her last week and she's been fine. That's her first direct "dairy". She's been drinking coconut milk since she was 10 mos, but having it in her cereal since she was 6 mos. She's had some almond milk, but mostly just coconut.
My plan has always been to try stuff myself first and then give it to dd2. So I began with goat's milk/cheese when she was 6 mos, then I did yogurt (around 8mos), butter/milk in baked goods (9mos), then hard/aged cheeses (10 mos), and then small amounts of any kind of cheese (11mos). I accidentally had some milk in oatmeal about a month ago and she reacted to that, so I've not had any more regular milk and I'm probably not going to until she's weaned, it's just easier.
We've just started introducing goat's milk/cheese with her and I'll give that probably 3-4 weeks, then do yogurt, then butter/milk in baked goods etc. all very, very slowly - maybe every 3-4 weeks if she's doing well. She's been doing so well I just don't want to go back to the awful place we were in before the MSPI was diagnosed.