First time it happened was last year, I didn't have jb4. I had bt1. I'm beginning to think the turbo location has something to do with it. It's right behind cyl 1-2. It gets so hot when boosting that the temp affects the block and since cyl 2 is right in front of the turbo, it soaks up more heat. Cyl 1 also but the heat escapes from the external wall. Probable solution is to wrap the turbo all the way down to where the downpipe ends.
Might sound crazy but also makes sense since these cars are known to have cyl 2 issues from time to time.