99% of my rigs are the same design I was using 15 years ago.
The materials may have changed a little and I now use the knotless knot because it's so much bloody easier, but that's it.
I went down the rigs route and it didn't do me much good.
I was worrying too much about rigs and I started to lose confidence because I kept changing everything.
I don't mean to annoy you, but are you catching?
If you are, then don't worry.
If people are catching more than you, it's not because they are using the latest rig, it's because they have more fish in front of them or they are feeding/baiting in a way that the carp want.
BTW, the Korda rig book is very average.
If I had a copy I'd post it to you.