I was the 1st to quote you and I'm sorry if your post was genuine. I'm sorry for my less than welcoming post - just we, like every forum, occasionally get the odd new members with an oxymoronic/asinine post to get a rise out of others, and being blunt, someone with a group 50 insurance car posting their insurance is surprisingly expensive is like posting you like swimming but don't want to get wet...
I don't think anyone is envious of the car (I honestly believe Tesla is partially responsible for the insurance rise for us all, but that's a separate matter) - but it's still a group 50 £60k car that does 0-60 in 3 seconds, so it's hardly a Honda Civic.
Re your question whether a course will help. In my experience, nope, I've had IAM for 20+ years and it's done v little to help insurance. Yes, some companies acknowledge it and offer a discount, but they're typically the more expensive ones, so it's usually cheaper to go elsewhere. I've also noticed you typically get the same discount for joining a Facebook group and saying you're part of the UK owners club for the car.
If you're looking at Admiral, please check your policy, especially the mod section. They typically require any factory fitted option to be declared similar to a mod, otherwise it's theoretically not covered. So, they might seem cheaper than some others, as they're not covering to the similar lever. I'm not too sure what options are available with a T3 performance, but I'm guessing there could be 1 or 2 (ignoring the horrifically expensive autopilot things, which who knows whether they would pay that our or not).
In all honesty, if you're wanting to lower your insurance then you need to get a less risky car (or move to a less risky postcode). A MG4, Ionic or electric Golf would presumably solve your problem.