The reason I posted as I did was that I am aware of a certain individual who having got his CPL a number of years ago let his exam credit lapse before completing his IR. He subsequently got a very good non-aviation job, had kids etc...
He later did the IR exams and completed his IR, then did an MCC and self-funded type-rating. He now works part time as a FO on biz-jets. If this isn't legal I'm sure he, the operator and everyone else would appreciate someone posting the relevant regs.
Whilst I have a huge shelf full of ATPL material, I did the CPL/IR exams. The sections of the material which weren't relevant for CPL/IR were clearly marked and they had nothing to do with multi-crew; global climatology, transatlantic nav etc..