Thanks for getting in touch.
Please may I ask, have you tried to add multiple charts in a ListView control and have them render in the standard way (Android will draw them they come into view)? Do you have any specific reason why you cannot do this? The reason I ask is that this is a fairly common use-case, and should prove simpler than attempting off-screen screen capture.
One of my colleagues authored an interesting blog series on this subject, the first part of which can be found here:
To answer your question regarding off-screen capture, it isn't something that our snapshot function was designed to support. As such whilst others (such as the poster who started the thread in your link) have achieved this, it isn't an approach which we recommend. That said, we are regularly impressed by what our users can do with our products and we do certainly encourage our users to experiment with shinobi controls.
I would certainly suggest however that you take a look at the blog which I've linked to - it may provide you with a simpler approach to your use-case.
If you do specifically need to use off-screen snap shots then by all means post back and we will try to help you further.