I have a reply from Micromark Technical
"Thank you for your recent e-mail, you can connect the light your way if you wish,the reason that we say to use a fused spur is so you can isolate the lights should you ever need to carry out any work on them and of course you cannot put a fused spur on a lighting ring."
Good news Quite a quick reply too, though not that impressive an answer for a technical department - perhaps I should make allowances for something lost in translation...
Of course you can put a fused spur on a lighting circuit (when was the last time anyone saw a lighting ring?) - its just that there is rarely any need.
Anyway, I would just go straight from the light to the unfused 2A plug, assuming your check confirmed 5A fusing on this circuit?
Gavin