Here at the beginning of the sentence, we have thou hast and a conjoined hast in the earliest text (“and thou hast not feared them and hast not sought thine own life”). But this is then conjoined with the biblically styled hath (“but hath sought my will”) rather than with hast. In the 1837 edition, the hath was emended to the plural have, which was still not correct for the subject pronoun thou. Finally, the 1907 LDS vest-pocket edition (and later the 1920 LDS edition, probably independently) supplied the standard hast in the LDS text. Elsewhere in the earliest text, there is one other example of a conjoined predicate of this nature:
And once more the 1907 and 1920 LDS editions made the change to the correct hast. The critical text will restore these two instances of and hath conjoined with thou hast. Note that the biblically styled hath was acceptable in this construction because the thou and the hath do not occur adjacent to each other, neither as thou hath nor as hath thou. There are no instances in the original text of that kind of usage.
Summary: Restore the two instances (in Helaman 10:4 and Ether 3:3) of and hath conjoined with a preceding thou hast, the reading of the earliest extant text (the printer’s manuscript in both cases).