Personally, I think anyone who uses a CPC as a ripcord is just a butcher. I've been taught to do it in the past - but it really isn't what it was designed for.
I have a cheaper version of those CK strippers and it's my main tool for the job. For getting close to the box entry, just pull in sime if the slack, strip, push it back. What do you mean, you can't do that when the cable is bedded in plaster - what sort of bodger doesn't take the conduit into the box
They are great for small sizes of T&E, but IME 2.5 is pushing it. 1mm is a doddle.
I also have a different Jokari tool for cutting into the sheath on round cable - twirl it once around for a clean circumferential cut and in one movement pull it along for a longitudinal cut - then peel back and pull off the sheath.
For larger T&E I use a knife - using a technique designed to avoid injury.
And never underestimate the utility of shear type cutters !
Of course, only skilled use of a knife is any good where the cable manufacturer "forgot" the talc and the sheath is welded to the cores