Outlook 365 for Mobile app - Compose window support for Office JS add-ins

We are exploring the new Office JS add-ons model for Outlook for mobile apps and wanted to integrate our product with iOS/Android apps. While exploring the new Office JS model, we didn't see any way to integrate the product with compose window. Task-pane or commandBar way of integration is missing for compose window.

Compose window task-pane or commandBar integration is common use case among iOS/Android users. While composing emails, the following use cases are common in industry:

1. Users want to insert documents or attach emails from 3rd part repository or storage or from content management software.
2. When user sends an email, they want to keep a copy of the email in the repository also

Currently these use cases are not possible with add-in model. But it is supported in desktop version as well as web version of add-ins. Without these use cases support, users wont adapt our solutions. So this is required for more user adaptability.