If bam thought shinwonryu would be effective against gado he would say so, that how the story is written on a straight forward manner.
Bam cancelling karaka attack isn't true when Evan grabbed him the attack flashed passed him, shinwonryu cancelled a small part of the attack, it was sleeping Yama and it just broke his grip, when Yama went to attack just use shinwonryu to knock him back but he didn't, cause he knows already, shinwonryu is powerful but it's still limited to bam output, that why red t with shinwonryu was shown as capable of taking gado leg, siu is giving all the answers to your opinion if just take it for what it is, instead of the speculation.
Bam is powerful but he is clearly limited to the shinsu on a given floor irregular or not, the loops would have no effect against gado nor shinwonryu or even the thorn ignition, cause the limit is set thus red t metamorphosis had to become thing, siu is being consistent imo.
Don't see rush for bam having ranker strength, when he couldn't even approach doom with loopsxorb combo which I assume is his strongest base shinsu skill, don't look down on highrankers just to bam over on them, he is not urek type character or there would be no tension in the story just 1 percent everyone.
Imo when base bam is truly ranker strength he will defeat them as easy as he does regulars, for now 1v1 is his limit, now way base can take 3 ranker on at the same time and there is surely elite rankers who aren't advance rankers either, can't just skip levels like that.