I currently train Iwama style as well and I have been curious about the IP of Dan Harden and his method of 'giving one the tools to develop it' and if anything like it is found within the syllabus we train with... especially Tai no Henko, Morote Kokyu Nage and suwari waza Kokyu-ho.
Even IF you are aware and trying to be mindful of what you 'should' be getting out of it (IP stuff) well, from personal experience I feel that could be a lot of trial and error and the time could be better spent if you can find someone who can clearly and decisively show and explain it to you.
Your post has convinced me that even if the path of the Iwama training method has the potential (given the teacher knows and the student is capable and understands) the method itself is not efficient enough in establishing the Aiki/IP aspect that would drive all intended 'waza'.
I want for nothing more than to do what you have done. Go and learn, record (even if only on paper) everything I can from a seminar, build it into my training and sneak it into the method the dojo follows if necessary to develop Aiki in our Aikido.
I missed the July seminar and this December one as well. I cannot wait to see the 2014 schedule so I can take steps to ensure I will not miss the next even if it means flying all the way to the USA and following Dan around the west coast for a few of them. Are the seminars cheaper by the dozen?