Multiple Canvas Snapshots

In my activity I have one layout with multiple layers. The last layer is a certificate my students submit to proof (as best as I'm able) they completed the activity. I have it so there's a button they press to begin the snapshot so they can save it to their system. I also have the system take a canvas snapshot of a picture they make about halfway through the activity and transfer it to the last layer. I can get each to work on their own but not together. When I try to do the full activity it gives me an error message when the system tries to take a snapshot of the student-drawn picture Is there a way I can include both canvas snapshots?

In my activity I have one layout with multiple layers. The last layer is a certificate my students submit to proof (as best as I'm able) they completed the activity. I have it so there's a button they press to begin the snapshot so they can save it to their system. I also have the system take a canvas snapshot of a picture they make about halfway through the activity and transfer it to the last layer. I can get each to work on their own but not together. When I try to do the full activity it gives me an error message when the system tries to take a snapshot of the student-drawn picture Is there a way I can include both canvas snapshots?

Blackhornet has amended R0J0hound's excellent Paster plugin to include a 'paste layer' option. May be worth a look.

This may seem like a silly questions but how do you download the plugin? I extracted the files for the paster plugin but when I try to open the example it gives me an error message.

Or would there be a way to shrink the layer and move its position so it shows up in a predetermined box on the final layer?