Migrating from old VR system (which worked) to the new XR system (2020.1.11f1)

Having been forced to migrate to the new XR system i have a showstopper problem
Either I keep the old Google VR folder and tools in order to navigate the game in Editor mode; for testing this is vital but then I can’t build the apk as get errors relating to virtual keyboard:
error CS0246: The type or namespace name ‘AndroidNativeKeyboardProvider’ could not be found (are you missing a using directive or an assembly reference?)

To fix this and successfully build my apk, I have to delete the GoogleVR folder, and in doing so i lose the ability to test the app in the editor and I can’t control my scene with the gaze function in Google Cardboard. I have lost the reticle pointer- this is critical as am building for lowest common denominator with Google Cardboard, no controllers.

Further, I can’t install version 2019.2 (which I believe having watched some tutorials is the latest version that works properly) as this is no longer available from The Hub, and downloading from archive doesn’t allow you to install the modules, android and iOs which are fundamental.

Is this really the situation? I have been learning/working on my first project for the last 9 months and currently all that work is for nothing.

Please, if anyone knows the solution to this mess, please let me know

Older Unity versions are possible to install with Unity Hub, just click on Add → download archive → then select version and click the green button.

https://unity3d.com/get-unity/download/archive

how did i miss that? thank you