Don't forget the cloud separation requirements when above 3000 feet. These requirements may have the effect of pushing you up or forcing you down into controlled airspace or some other place you do not want to be .
Of course those with a lifetime CAA licence, and even with no instrument qualification, may legally opt to declare themseves IFR with no relevant cloud separation minima, provided they maintain VMC
And then there are those who might think that cloud separation minima are legally undetectable and therefore unenforceable
