My experience was that I needed the Multi before commencing the JAR approved IR but that I think was more for scheduling and continuity. JUST MAKE SURE YOU HAVE THE RIGHT AMOUNT OF MULTI HOURS ie 7 inc test in VFR conditions before your IR.
In my experience (very recent) I found it better to do the multi rating prior to the IR (after the CPL though), as a kind of 'get to know your aircraft' exercise. I'm pleased to say it appears to be paying off.
Also bear in mind you can do the CPL in a twin and this counts as a multi rating and as the 'complex a/c' part of the cpl. but remember things happen a lot quicker in a twin and I know my VFR nav was piss poor even at single engine speeds!!
ENJOY and well done on getting the ellusive ATPL exam credits!!
BJ
