Thanks. Having some issues with the Xcode instruments rebooting the device whenever I try and run the profiler. I tested with a basic listbox in a new project and the performance is fine, so its probably something to do with my code. I'm also struggling with incredibly long build times for release builds - up to about 10 mins at a time spent on the linking stage.
I'll have a look at using a native listview / UITableListView. In some ways I'd like to use native UI for navigation and list elements as they make smooth transitions and scrolling so much better. For iOS this is not so bad sd we have the UIViewComponent class but for Android this is a whole other kettle of fish and requires a fair bit of restructuring.
Anyhow, I'll report back with my findings when I manage to get the profiler working.