I'm a bit confused as to what your question is? Are you asking how much humidification is required for a 28 qt. coolidor? Perhaps your just wondering what it is that CI sent you? (sounds like a boveda pack... they come is different rh levels and sizes)
Also, most coolidors have the best seals possible IMHO.
What number of oatmeal stouts are you on?
(After re-reading I think I have an answer to your question:
http://www.bovedainc.com/solutions/tobacco/tobacco-faq/ )