Go to my Custom Xamarin Demos repository on GitHub. Scroll down until you see my Render Image example.
In the Render Image Example's README, you will find instructions on how to get a PNG or JPG (with PDF support) from a Xamarin.Forms UI element by calling a simple method:
This gives you a byte array that you can do whatever you want with (i.e. save to a file, send to an API, anything).
As far as knowing when such a feature is officially added, you can click the Follow button in the Feature Request that you already commented on. At this time the Feature Request is marked as Unplanned. You'll be notified if/when the item 's status changes.
For transparency, I will reply to that Feature request with the same information I provided about so that developers can see who to do this themselves without needing to wait for a feature to be implemented.
Lance | Manager - Technical Support