The earliest text uses the past-tense form pled; the 1830 compositor spelled this past-tense form as plead, which even today is recognized as an alternative spelling for pled (according to MerriamWebster’s Collegiate Dictionary). The 1879 LDS edition replaced this instance of the past-tense form plead with the alternative pleaded, probably because plead was misinterpreted as the presenttense form (and was therefore thought to be an error).
In most printed editions of the Book of Mormon, the past-tense form for the verb plead has normally been spelled as the potentially confusing plead rather than the transparent spelling pled:
The printer’s manuscript always spelled the past-tense form as pled, but the 1830 compositor consistently set it as plead. The 1981 LDS edition changed the instance of plead in Alma 22:20 to pled, but left the two other instances of the past-tense plead. The original manuscript is extant for Alma 47:15 and reads plead, which was copied as pled into 𝓟. For the case in Alma 22:20, 𝓟 actually read fled, which suggests that the original manuscript there probably read pled rather than plead. John Gilbert (the 1830 compositor) corrected fled to pled in 𝓟, but then set plead (as he did everywhere else).
In the original text, there are no occurrences of the alternative past-tense form pleaded. The use of the spelling plead for the past tense can cause potential reading problems, thus the critical text will spell all occurrences of the past-tense form as pled and not plead, reserving that spelling for the forms of the verb plead that are pronounced /plid/. Further, since the original text never used the past-tense form pleaded, the original pled should be restored in Alma 1:11.
Summary: Restore the original past-tense form pled in Alma 1:11; use the spelling pled throughout the text for the past-tense form of the verb plead, thus avoiding the alternative but confusing plead for the past-tense form.