As I already said, SuperRes doesn't like ringing.
I wouldn't use SuperRes with super-xbr. Instead I'd use super-xbr with a low sharpness setting + Adaptive Sharpen, then ringing is far less of a problem.
NNEDI3 64 quadrupling + SR (strength 3, sharpness 1, ll off):
super-xbr 100 + SR:
Jinc AR + SR:
super-xbr simply looks terrible in this example. I'd even prefer Jinc, as it has less ringing problems.
NNEDI3 + SuperRes is best by far.