I've just been discussing The Range Irish Stout kit on another thread. I'm going to do this one again, so I'm VERY interested in your brew! A few questions, if I may?
The Irish Stout instructions calls for a 23 litre batch. So are you saying that you only brew with a 13 litre batch? That's very short. What is the OG? Does it work because you're not adding the 1kg dextrose, but instead replacing with smaller amounts of fermentable sugars?
Could you explain the hopping details? The way I read your post is that you make a tea with hops (if so, which type?), then dry hop with the supplied kit hops? If so, do you dry hop as per instructions i.e. after 7 days? I actually let my fermentation go for 2 weeks (following the 2/2/2 rule) and added hops at 11 days.