Thanks again for your reply Paco, will take that into consideration.
With regards to simply making an image right after a format, it's something I've considered doing in the past but unfortunately sometimes I make hardware changes that necessitate a completely fresh install with a new software setup. The 2 install limit is just too restrictive and frankly it's absurd that the software is controlled in such a way when you need to splurge £500 on it to begin with (itself an extortionate amount). Unfortunately, this kind of thing seems common from my search for a suitable course - the Nordian ATPLs ebooks for example stop functioning after only 18 months unless you pay another extortionate fee (not clear on their website, but it seems to be the entire cost, about 560 euros) to keep them accessible!
I've had a look at a few more schools, and Flying Time was another I came across. I spoke to them and they're willing to be flexible and condense the revision courses to only 3 days for me. The person I spoke to wasn't too clear on how this is organised, but I'd obviously get a guarantee that this is definitely doable before paying up for a course as it would be one of the deciding factors for enrolling. They use the Nordian textbooks - does anyone have any feedback on these and how they compare to the others?