3F is the required solo jump for juniors this season. 3Lz isn't her best jump so I feel like she'd probably still do 3F-3T if the solo jump was different.I haven't followed Petrosyan very closely, so correct me if I am wrong but compared to JRussNats, she seems to have upped her technical components by switching her 3F-3T to a 3Lz-3T, even though her Lz was at times quite wonky and troublesome. Moreover, I find her speed and skating quality very high for her age and also in comparison to the other athletes from her group. I definitely think that in PCS she is far better than Zhilina, the latter has though amazing jumps.
I agree that her PCS is usually better than Zhilina's, but Adelia wasn't at her best PCS-wise yesterday and Veronika was better than usual. IIRC, Ted said on the broadcast that Adelia's practices were rough so that was likely on her mind during the program.
It all depends on how others will skate.