Here 𝓞 is not extant for the verb bore (the corrected reading in 𝓟 and the reading of all the printed editions). However, when Oliver Cowdery first attempted to write this word in 𝓟, he wrote the auxiliary verb did, as if to write did bear. But he never wrote the bear in 𝓟; instead, he immediately crossed out the did and supralinearly wrote bore. This error and its correction in 𝓟 suggest that 𝓞 read as bare, not bore; a reading like bore in 𝓞 would not have led as easily to did bear as bare would have. In support of this proposed momentary error in 𝓟, there is one very clear example, although not by Oliver Cowdery but by the 1830 compositor, where bare was changed to did bear:
Here in Alma 53:13, the critical text will assume that 𝓞 read bare. Another possibility is that 𝓞 read bear, which could have easily led to an error like did bear but less likely to bore as a replacement. The past-tense form bore has entered the text in two instances, and in each case it came from bare, not bear:
There is only one firm instance of bore in the earliest text, in Alma 1:25 (“and they bore with patience the persecution”), but this is not extant in 𝓞. As explained under 1 Nephi 11:7, there are numerous instances of bare in the earliest text, so the most reasonable reading for the past-tense form for the verb bear in 𝓞 (and in the original text) for Alma 53:13 is bare: “when they saw the danger and the many afflictions and tribulations which the Nephites bare for them”.
Summary: Emend Alma 53:13 so that the past-tense form of the verb bear is bare, the most probable reading in 𝓞 and the one that best explains why Oliver Cowdery initially wrote did in 𝓟 and then corrected it to bore.