If you are taking requests : ), allowing for the automatic offsetting of the image to line up at the map click point would be a nice option as well. For example, map markers, more often than not, you'd want to automatically align it to the center & bottom of the marker. Also, when I was testing the tutorial code out, I noticed that it does not appear to automatically provide the Width and Height of the streamed image from the assembly (though it hints this would be auto set if none were manually forced)
So... for example, I had to force the Height and Width explicitly, and then I was able to do:
pinSymbol.Height = 22;
pinSymbol.Width = 22;
pinSymbol.OffsetY = pinSymbol.Height / 2;
Without setting them explictly, they were always resolving as 0 height and width for that calculation.
Just further food for thought. Thank you for a very nice API. It's been nice to work with. Also thank you for considering more automatic handling that lines up with other xamarin forms methods of image resolution choices.