After watching Sima's videos, I think her jumps have definitely improved a lot. But I am surprised to see that her skating skills and speed regressed. She used to be fast with good edge when she was a junior. Even her upper body movement looks very stiff and old now. Except for her 3-3, she does not have any flow going into jumps. It feels she is jumping on a floor, yet she managed to jump all her triples. She has the oddest jump technique probably from her coach before Eteri and it is still affecting her.
With Serafima you have to look at the whole picture, cause if you compare it now to what she was with Eteri, she is still not at this level.
https://www.youtube.com/watch?v=wHb2YiJEEbA
(2015 RN FP)
After Eteri she had to come back to SPB to her former coach Alina Pisarenko, which she is not nearly as experienced as Eteri or even has the same resources, the environment wasn't as competitive,... (personally i think this was a mistake from the Federation: she was junior world silver medalist, we know how Figure Skating is state funded in Russia, they should have suggested her some better option in SPB) anyway the coach wanted her to train the 4s and got injured because of it, she skipped JGP events because apparently she wasn't ready, and then showed up in Spain and she was a hot mess.
https://www.youtube.com/watch?v=W5UMhG7dFPM
(you can see in this very competition how she was still the great skater of the year before with excellent skating skills, but confidence especially with the jumps was starting to fade away, i'd say partially because of the ridiculous complexity of that program)
OT: i'm seeing some of those issues Sima had with Pisarenko especially with the jumps, now with Sofia Moroz. /OT
She then switched to Rukavicin, and she tried to relearn everything with him but things got worse (Rukavicin also teaches a weird technique, with those wide legs in the air), and confidence was completely lost at that point.
https://www.youtube.com/watch?v=NbfLznQOGVg
(This was not even one of her worse performances during those days but you can see she couldn't do 3-3 anymore, uncertainty with every triple jump)
After Rukavicin she wanted to quit with FS (possibly she didn't train for months), Plushenko convinced her to try again on his group in late september of last year and they started reworking everything, starting with the jumps with programs lighter in choreography in order to bring back the consistency and it worked.
https://www.youtube.com/watch?v=zTFr1QpjMJY
(you can see the gaps in this program but spins were faster compared to the previous year and she fought for all the jumps)
And now with Turenko, her 3f-3t and other triples got bigger and cleaner, and she is building more stamina, it is still a work in progress
https://www.youtube.com/watch?v=uolSRgHMeOo
Every competiton she is looking more trained, more confident, she is adding more choreography, she is consistent with the jumps and she is getting new PBs, i think she can show up in a very good form at Nationals (if she is going, fingers crossed).
Thankfully Turenko seems a coach who cares about skating skills and artistry so i think she will keep improving on that as well.