I would have Rungsavai as a favorite. He is ring number one in the division and Rodriguez is 22, in his second title fight and is jumping up two weights.
It's a pick 'em for me. Rungsavai post-Gonzalez would probably lay Rodriguez out but the suspicion is he is on the decline and at the lower weights, that decline can become precipitous very quickly. Gonzalez took on Cuadras at fairly late notice and won handily. He is young, very talented and very much on the up.
On the other side of the coin, as you said, despite his big win, Rodriguez is new to this level and up against a teak tough veteran. Rungsavai is also a beast at 115 and hits incredibly hard; harder than anyone Rodriguez has ever faced. I also suspect Cuadras is over the hill and think Rungsavai would have beaten him had the fight not been postponed. I've gone Rungsavai at 7/2 anyway and 13/2 to win via stoppage; those odds are far too long IMO.
WHY THE FUCK IS THAT PISS HEAD STILL GETTING A LICENSE IN THE FIRST PLACE?
New to boxing mate?