As the Head of Training of a school that trains massively for the IR I can assure you the U.K. IMC Rating is a waste of time towards your commercial IR. It is generally taught by people who have no experience of commercial IFR Ops and is usually taught badly. It means as a school we have to unwind all the bad habits and that takes longer than just teaching someone from zero.
You also need to consider the future if you are wanting a career in aviation as the U.K. leaves EASA in just over 8 weeks and the U.K. is not exactly a vibrant aviation industry. This means you need to look at another EASA state and as the U.K. IMC rating is not valid on any European licence nor does any of the training count toward a full IR it will be a wasted investment.