Ok. I didn't know that Slutskaya was the first. For Medvedeva i was suspecting the arm variation + 444 transitions. But since it's a trend in Eteri's camp since 2014-2015 season...Mao would 100% be in this list! I merely forgot to put her name down.
Slutskaya was attempting two triple triples in her programs. Medvedeva had the most transitions and she had the difficult tano and rippon jump variations in her programs before they were normalized.
She's indeed the first on senior level, the others were too young.