workflowuser This is what I suspected from the docs and a quick look at the guidebridge code. Thanks for confirming.
I will be looking to use the guidestate Json for restoring, the reason for this question was due to a limitation with submitting the guidestate (it doesn't appear to be submitted as part of the Post request). I will accept this answer and raise a new question about that, it would be great if you could take a look at that as well! Bit of a catch 22