I certainly wouldnt want to start my training with this hanging over it
If you already have an IMC rating and perhaps some instrument time in your log book then getting the FAA IR can be the cheapest route to getting a CAA IR. This is because your existing instrument time (including the IMC rating) can count towards your FAA IR, but not a CAA one. However, once you have your FAA IR you can convert to the CAA one with only 15 more hours.
Unfortunately it makes no difference to the need for the ground school requirements.