There are three passive verb phrases in this long after-clause. Originally, the first verb phrase read “have been nursed”, and the second and third read “shall be carried”. In his editing of the printer’s manuscript for the 1837 edition, Joseph Smith changed the last two to agree with the first, so that all three read “have been” in 𝓟. But in the 1837 edition, the first one was changed to “shall be”, as if to agree with the original “shall be” in the two following cases. It is possible that Joseph considered making all three verb phrases read as “shall be”. Perhaps Joseph (or an assistant) changed the first passive verb phrase to “shall be” in the copy of the 1830 Book of Mormon that served as the copy-text for typesetting the 1837 edition; then later the changes for the second and third cases were also transferred from 𝓟 to that copy. In any event, the 1837 edition ended up by reversing all three verb phrases, thus retaining the inconsistency of the original passage.
In the King James Bible, which this passage in 1 Nephi 22:6 paraphrases, the future modal shall is used. This use of shall agrees with the second and third cases in the Book of Mormon passage, which originally had shall:
There is further agreement between the King James Bible’s “shall be carried” and the two occurrences of the same passive verb phrase in the original Book of Mormon text.
The critical text will follow the reading of the original manuscript (“have been … shall be … shall be”). As far as the first case is concerned, there is nothing wrong with the present perfect passive in after-clauses, even when the reference is to the future. In fact, the very next verse has an example that has never been edited:
Summary: Restore in 1 Nephi 22:6 the three original verb phrases in the after-clause; according to his editing of the printer’s manuscript, Joseph Smith intended for all three verb phrases to read the same (as the perfect passive “have been”); the 1837 edition followed this editing for the second and third cases but changed the first verb phrase to “shall be”, which resulted in a systematic reversal of the original verb phrase usage in this after-clause.