A few opinions I have in regards to the Japanese girls~
Watching Rena's summer competition performances it looked to me like she might be in the process of adjusting to growing taller and longer which could be affecting her jumps
As far as Kaoruko's FS inconsistency, I blame this on years of being harshly yet justifiably penalized for under-rotations
With her gorgeous basics and its limited number of jumps she's usually able to score decently well in a SP
However, during the FS she often seems to put way too much effort into rotating her jumps compromising her technique and consistency
In most cases jump rotation can be worked on and improved and Kaoruko with the help of her team seem to be doing their best to overcome this issue
For now, as she did today, if Kaoruko focuses on just skating her best, highlighting her high quality elements rather than concentrating so much on jumps, she's more than capable of delivering clean(ish) performances.