Why isn't UIToolkit or AppUI using the native keyboard?

They mobile touch keyboard mentioned here:

…is what comes up when you focus an input textField in UIToolkit. It’s not particularly performant, and multiple options for keyboard type produce the same keyboard. Is there a solution for using the native keyboard other than solutions like React Native or Flutter?

Check out UMI. It literally just overlays a native input over a tmpro textfield. You get emojis, copy/paste, different keyboard types and so on. Unfortunately it is UGUI only, but I ended up creating a canvas above my uitk document and enabling it whenever my custom text fields are pressed. Its a dumb solution to a dumb problem.