Hi Simon,
Not sure if you have sat your AM2 yet? If not I sat mine 2 weeks ago and luckily managed to pass 1st time. I have quite a bit of info on it if your interested (or anyone else).
Let me know and I either post or PM me and I will email you the info.
However the most stressful bits was the fault finding, there are 7 faults (you have to get 5). Mine were
1. RCBO keeps tripping. Ring Main - Short circuit between Neutral & Earth. You have to tell them between what two points, how you would rectify, and the tests you would perform to ensure the fix.
2. Light circuit not working - No continuity on neutral, again between what points, fix and test(s).
3. Motor not working - No continuity on neutral from CU to starter. Again fix and test(s).
4. Data fault short between pins 7 & 8. in your pack you will have the user guide to the test meter. This will show a list of all the faults the unit can detect with what lights up for each fault. Again fix and test(s).
5. Gas bonding - reading was 2.58 ohms. Not within the 0.05 ohms expected. Again fix and test(s).
6. 16A 3 phase socket had low IR reading, from socket back to isolator. Between all phases and Earth, also between All phases & neutral. Again fix and test(s).
7. CH not working although programmer calling for heat and room thermostat calling for heat. I had no continuity from Room thermostat L2 to pin 14 (i think) on DIN rail. Again fix and test(s).
Follow the spec in the pack and you should be ok. If during Test and Inspection you find any problems, you are allowed to fix.
Don't panic with the S plan. It is the easiest part of the install. Point to point and lots of it is pre-wired allow at least an hour. They do require you to use ferrules on the flex cables as easier to push into the DIN rail.
Good luck hope this helps.