It´s not only time. Openwhisper System was not cooperative in helping us with all the information we need to make a real good native App including push notifications. I can see their point about amateurs weakening security, but on the other hand other systems like Matrix seem to be more responsive to communities.
Besides that, file sharing does not work inside Anbox because it would need a ton of things replicating hardware access to apks, and also the folder structure is totally different between UT and Android. I doubt this will come soon.