Hope this isn't too nuanced.
There's a pretty established rule in the Shulchan Aruch that when he writes a law, and then writes "some say" (ויש אומרים) something else, he's ruling like the first opinion, and not like the "some say". He just wants you to be aware of the second opinion.
Now, sometimes the Shulchan Aruch writes a different expression, "there are some who require" (יש מי שמצריך). I would think this is no different than the rule above. However, here's an example where that seems to not hold true (Yoreh Deah 69:19):
אחר שנמלח הבשר והודח מותר ליתנו אפילו במים שאינן רותחין ויש מי שמצריך ליתנו במים רותחין
After the meat has been salted and rinsed, it is permissible to put it in boiling water. And there are some who require you to put it in boiling water.
The Shach (§ 78) there writes:
ולהכי הביא המחבר סברא זו דהיכא דאפשר יש לחוש לעשות כן וכמ"ש בב"י
And this is the reason that the Shulchan Aruch brought this opinion, since in cases that it's possible one should be diligent to do so, like he writes in his Beis Yosef.
Where does the Shach see this is the intent of the Shulchan Aruch? He does bring that the Shulchan Aruch in his Beis Yosef writes that when possible one should put it in boiling water, but who says when he wrote his Shulchan Aruch he still held so? Does the Shach somehow see this from the wording of "יש מי שמצריך". Meaning, if the Shulchan Aruch didn't hold of it, he would have written ויש אומרים? Is this is a rule that is demonstrable elsewhere? Or something specific to here...