Both the original and printer’s manuscripts have the word yea here in Alma 28:12. The 1830 typesetter accidentally omitted the yea. The 1908 RLDS edition restored the yea to the RLDS text. There is nothing wrong with “yea and even” followed directly by the finite verb (the subject being ellipted). This kind of transition is found, for instance, earlier in the text:
Summary: Restore the earlier yea in Alma 28:12 since both manuscripts have it; the construction “yea and even” immediately followed by the finite verb occurs elsewhere in the text.