Cresselia S -> A: Yes
Thundurus S -> A: Yes
Sylveon S -> A: Yes
Kanga and Lando-T should be the only mons in S atm, imo.
Apart from that, there is some stuff I have no idea how someone could have come up with it:
Raikou A -> B
Milotic A -> B
Rotom-H A -> B
Salamence A -> B
Gengar B -> A
Mega...