Briefly as I am planning for the next few days.
The 15 hours is not needed if you pass an FI test, not a Type Rating test with an FIE.
In amendment 3 they missed out the 15hour requirement due to a typo.
It is back in,in amendment 6 and is in one of the paragraphs included by AIC 72/2007 (my favourite subject). The para referred to above by albyskoons, 2.310a(6)
The only mention I can find of 15 hours in the last 12 months is for the renewal of an FI rating in 2.320G and that doesn't say it has to be on one type.