AndroidNZ posted an article about disabling Fast Dormancy on a SGS3 which no longer has the useful feature in the *#9900*# (or whatever) menu. Since there didn't seem to be any obvious way of disabling this in CM9 - if it even supports it, I can't find any conclusive info one way or another, and as expected, the devs who would know such a thing don't respond to questions.
I figured I'd give GokhanMoral's app that he made based on the article on AndroidNZ a go, and it _seems_ to work. It may be a placebo, but battery life seems to have improved dramatically, and given that Telecom's lack of support for the feature used to result in significant battery drain on the stock ROM on my SGS2 and the current Galaxy Note, it seems promising.
The app is here: https://play.google.com/store/apps/details?id=com.gokhanmoral.fastdormancytoggle.i9300&feature=search_result
The AndroidNZ article is here: http://www.androidnz.net/2012/06/at-your-own-risk-how-to-disable-fast.html
I applied it to a Galaxy Note running the current CM9 build. As said, I may be completely imagining things, but the app itself seems to think it's working, for what that may be worth.
Am I dreaming? Anyone else game to try it? If nothing else, it's not broken anything that I can find.
I still seem to be getting the secril_fd-interface wakelocks, but around 30s of wakelock in half an hour could be worse.