Swift UI vs Flutter

I honestly think that both Swift UI and flutter are great frameworks. And I found them both really easy to use and get started with. But what I've heard from different developers or like seen on Reddit is that when you want to build really custom stuff or kind of branch out, that gets pretty difficult with Swift UI. So do you need to open up the channel with them and explain to them how widgets work and let them start to copy flutter a little bit more? I don't know. They kind of like to keep things a bit more rigid, it seems in their developer ecosystem so they might be okay with that.