Scribe 2 of 𝓟 initially wrote the name Minon as Minen. Then almost immediately he overwrote the e with an o, presumably the reading of the original manuscript. Scribe 2 frequently miswrote o’s as e’s. For instance, earlier on this page of 𝓟 (near the end of line 6 on page 174), scribe 2 initially wrote two as twe; then almost immediately he corrected the e by overwriting it with an o. In the following example, scribe 2’s e /o once more involves a name:
Book of Mormon names can end in either en or on, but there are only two examples with en (namely, Kishcumen and Kumen) while there are 21 that end in on (including common ones like Ammon, Ammoron, Amulon, Gaddianton, Jershon, Morionton, Mormon, Moron, Parhoron, and Shiblon). The most reasonable solution here in Alma 2:24 is to follow scribe 2’s corrected reading in 𝓟 since there would have been no motivation for him to have edited Minen to Minon.
Summary: Maintain the corrected spelling in 𝓟 for the land Minon, mentioned only here in Alma 2:24.