Normally, the Book of Mormon text prefers the plural pronoun form ye in subject position, but there are cases where the original text has you (which is what we expect in modern English). There has been some tendency in the text to replace ye with you, but here in Mosiah 4:14 Oliver Cowdery corrected a ye to you in 𝓟. The correction comes at the end of a manuscript line. Oliver initially wrote ye and then overwrote the e with an o; but then he decided that there wasn’t enough room for the final u, so he crossed out what he had written and supralinearly inserted you right above the crossed-out ye /yo. He even had trouble with his supralinear you: he first wrote yu and then inserted the o between the y and the u. Oliver redipped his quill before supralinearly inserting the you since the level of ink flow is slightly heavier for the you as well as for the crossout and the insert mark in this correction. All in all, the correction of ye to you looks fairly immediate.
Despite all these efforts of Oliver’s to write the correct you, the 1830 compositor set ye, the standard biblical subject form for the second person plural pronoun; this ye has continued in all of the subsequently printed editions. Elsewhere in king Benjamin’s discourse, there are examples of you serving as the subject pronoun in place of the expected biblical ye, including two more in this chapter of Mosiah:
Note that in both these instances there are nearby instances of ye. Overall, the biblical form ye dominates the text; for instance, in the original text for king Benjamin’s discourse there are 122 examples of ye but only 10 of you. For a complete discussion of the variation between ye and you in subject position, see ye in volume 3.
Summary: Follow Oliver Cowdery’s correction of ye to you in Mosiah 4:14 since you most probably represents the reading of the original manuscript and not editing on Oliver’s part; maintain the subject you in those cases where the earliest textual evidence supports it.