Then, when it was all polished up and ready to submit to upstream, I find this:
Of course, that was disappointing to read, but it's his call. So, I went to Plurk and sent them an email (through their contact us form) asking if they would state that using the "Unofficial API" within the terms of service (of course) is something they're okay with. Hopefully they'll be cool with it and say so publicly. Then, I can send in my patch.