I'm not comfortable with rejecting requests just because they fail to percent-encode the @ so my vote is for that test to be relaxed a bit.
Overall I'm impressed with how easy it was to get this running. Switching from the quickstart instructions to testing my own instance just involved copying the "gargron" example test plan and changing a few parameters. It couldn't have been simpler.
I haven't looked at the UBOS stuff yet. That will have to wait for another day.