It's not too early to "commit" to SwiftUI. Just remember that "committing" doesn't mean writing every last bit of UI code in SwiftUI. At this stage, I think the best approach is to be using both UIKit and SwiftUI, and use whichever framework is better for implementing whatever specific features you're implementing.

For example, say I'm presenting a modal with a simple form. I'd use UIKit's UINavigationContoller to present the modal view, and within the modal's view, I'd have a UIHostingController which encapsulates the SwiftUI-defined form user interface. I can define form layouts (and other simple layouts) much quicker in SwiftUI than I can in UIKit, so I'm finding SwiftUI to be very helpful in that regard.