one note about the patch.
The following is incorrect:
+ // However, you can only make that call if you know that the image is
+ // EBS-backed, and there is no way to find this out (before launch) in
+ // jclouds at present
After you build a template, but before you create the nodes, you can check the image in the resolved template.
For example, we are already doing something similar in
basically, we can add BootstrapTemplate.mapEphemeralIfImageIsEBSBacked
I think the above is the missing link in this patch. I hope it helps!