I think the problem isn't the FI course, it's finding somewhere to do just the CPL theory. When I did mine, back in the 1980s, I did 'distance learning' or correspondence course, as we used to call it, with PPSC at Bournemouth. I've heard recently that most places only do the full ATPL. This would be an excellent place for someone to refute this with an example.
I needed a Class 1 when I started instructing back in 2007 but the rules thankfully relaxed just as I got to 65 and was faced with ££££ of cost for a stress ECG, now happily on a Class 2, no problem with getting paid (not much, mind you!)
TOO