I would normally ask for height, but when you said no thrill that doesn't really matter. There is Suess land they would enjoy and there is a playground in JP they would like. But if they don't even like kiddie coasters, then the kiddie one in HP wouldn't work for them. Do they like spinning? There is a spinning one a little faster than the cups at MK. I assume rapids rides are out? There is a rapid and water drop one that isn't scary, but it could be considered thrill.
I will also say child swap works differently at Uni, in some ways it is better, but if your kids can't handle scary the lines on some rides you want to do child swap may not work. Everyone goes thru the line and then there is a waiting area for the parents to swap. It is much faster as parents because you don't go back thru, but I know sometimes my kids didn't like going thru some of the more scary lines.
I personally would look at the list of rides offered at IOA and ask them if they would ride it. That is what we typically do when looking at new parks. But my kids will do coasters, but not all coasters at all ages. So my 6 yr son won't do ice breaker that is too high for him, I debate with him about this since he will do infinity falls which is just as high lol. But I give them the control to decide. Some stuff they don't like because they consider it too baby. So we decide based on that whether the park is worth it.
