According to Xamarin Forms custom renderer documentation, custom renderers make it possible to develop custom Xamarin.Forms UI elements based on native objects of each supported platform.
This means that in order to write a Xamarin.Forms equivalent to our TerminalControl object, one would first have to implement a terminal control using native SDK features of each of the supported platforms, and then write a custom renderer for it to make it work as a Xamarin.Forms UI element.
An iOS terminal control would consist of an IScreen implementation that draws into an UIView. We will try looking into this and will hopefully release some sample code for it soon.